"Grandad and I will now have to go house-hunting," said Isobel after she won an all-English quarter-final against the English Under-16s champion, Lily-May Humphreys, a 14-year-old from Channels Golf Club, Essex. "At this moment we have nowhere to stay tonight!"
Wardle from Prestbury, which is south of Manchester, beat last year's championship runner-up, Marta Perez Sanmartin (Spain) by 4 and 3 in the morning third-round ties and then scored a 2 and 1 win over Humphreys.
"To be fair to Lily-May," said Isobel, the eighth seed. "It was a really good match and it could have gone either way. I was never down and that was an advantage because it meant she had to chase the game all the way but she did that rather well." Wardle was roughly level or one under par in a rising wind for the first 16 holes.
"The wind was quite strong by the time we got to the 17th tee and we both misjudged it and we both drove out of bounds. But a half in however many strokes it took was all that concerned me," said Isobel. Wardle went one up with a par at the third and the fifth was halved in birdie 3s. She went two up with a birdie 4 at the seventh and maintained that clear-cut lead until Lily-May won the 10th and the 11th with pars to square the contest.
"I wouldn't say I was getting anxious but I knew that the next hole, the 12th, was crucial to my hopes of winning," said Isobel.
"I had to stop her run of wins and get one myself which I did with a birdie 4. That put me back into a one-hole lead and I felt a lot better after that going into the closing holes.
"We both got up and down to halve the 14th in par and we both faced 4ft putts for par. I holed mine, Lily-May missed hers and that was me two up with two to play. Then we both drove out of bounds at the 17th but the hole was halved, leaving me the winner by 2 and 1.
"I've had a different part of my game on song each round. Earlier in the week, I drove very well. Today it was my short game and putting that carried me through.
"Win or lose on Saturday morning, this has to be my best performance at this level of the game."
Having beaten one 14-year-old, Wardle plays another in the semi-final - Alessia Nobilio from Italy, the 12th seed.
Alessia knocked out the No 4 seed, Paula Neira, a 17-year-old from Spain, in the quarter-finals after beating the No 5 seed from Sweden, Beatrice Wallin, by 4 and 3 in the round of the last 16.
Nobilio's victory in itself against Neira was very good but to achieved a 7 and 5 margin against a player of that quality was remarkable. The younger player got off to a flying start anad was three up after only five holes. The sixth was halved in birdie 3s before Nobilio won the seventh and the ninth to be five up at the turn.
Neira never won a hole. Her nightmare continued with losses at the 12th and 13th finishing a one-sided match that few would have predicted.
Julie Engstrom, at 15 the youngest ever winner in the long, long history of the Ladies' British Open Amateur Championship at Dundonald Links in June and the highest rated player in the field - she is ranked No 23 in the world, remains the favourite.
She had to go to the 20th, where she won with a bogey, in her morning match against
Germany's Esther Henseleit, the 14th qualifier, but she was back in impressive form in a 5 and 4 quarter-finals win over the 11th qualifier, Sofie Nielsen, a 17-year-old from Denmark.
Engstrom was roughly one or two under par in beating Nielsen by 5 and 4. One down to a birdie at the sixth, Julia climbed into the driving seat by winning the the seventh with a par, the eighth with a par and the ninth with a par to be two up at the turn.
The 10th was halved before the Swede set off another run that would clinch her place in the last four. Engstrom won the 12th with a par to go three up, the 13th with a birdie to go four up and the 14th with a par for a 5 and 4 success.
In the semi-finals, Julia will play Emilie Paltrinieri, the 15-year-old Italian, beaten the second seed, Norway's Madelene Stavnar by 5 and 3.
Stavnar, the favourite to beat the 39th qualifier, made a good start to be two up after four but that was as good as it got for her.
Paltrinieri won the sixth, seventh, eighth and ninth to transform a two-hole deficit into a two-hole lead.
There was no way back for Stavnar after her opponent birdied the 11th to go three up and went four up with a par at the 12th. Paltrinieri clinched an impressive 5 and 3 victory by winning the 15th.
England are assured of one representative in tomorrow morning's semi-finals of the Girls' British Open Amateur Championship at Royal St David's Golf Club, Harlech in North Wales.
That's because Lily-May Humphreys, only 14, from Channels Golf Club, Chelmsford, and Isobel Wardle, 16, from Prestbury, Cheshire, won their third-round ties this morning and, as luck would have it, they play each other in the first quarter-final off the tee this afternoon.
Humphreys won by one hole against Sweden's Sara Kjeliker who, as the last of the 64 match-play qualifiers, knocked out the top seed, her compatriot, Amanda Linner, in the first round.
Lily-May trailed for most of this morning's match - two down after four holes, still two down at the turn, and one down on the 14th tee.
But the English girl got her game together just when she needed it most and after squaring the match, she edged ahead over the closing holes to win by one hole. Lily-May was the 49th qualifier.
Isobel Wardle, the eighth seed, overpowered the Spanish girl who was the beaten finalist at West Kilbride in last year's championship - Marta Perez Sanmartin.
Wardle was two up after four, three up after nine and four up on the 11th tee. Sanmartin won a hole back to be three down playing 14 but she could not keep it up and Wardle won her place in the last eight by a 4 and 3 margin.
Paula Neira (Spain), the No 4 seed, won by 5 and 4 against Sweden's Pi-Lillebi Hermansson who beat Aboyne's Shannon McWilliam in the first round.
Neira trailed by one hole in the early stages but had a two-hole lead at the turn and went three up by winning the 10th. The writing was on the wall for the Swedish player when Neira went five up after 13.
She will now play Italy's Alessia Nobilio, the No 12 seed, who KO'd the No 5 seed from Sweden, Beatrice Wallin, who also lost in the third round of this championship 12 months ago.
Nobilio and Wallin were all square after four but, by the turn, Nobilio had established a three-hole lead which Wallin could not overcome as she went down by 4 and 3.
Sophie Nielsen (Denmark), the 11th qualifier, played her way into the last eight with a 3 and 1 win over Italy's Maria Vittoria Corbi. Nielsen took a grip of this game around the turn. The Dane was two up after nine and then won the 10th.
Corbi got a hole back to be two down on the 14th tee but that was as good as it got for her and the match ended on the 15th green.
British women's open amateur champion - the youngest ever - Julia Engstrom, 15 years old from Sweden, scrambled through into the last eight with a 20th hole victory over Esther Henseleit (Germany).
Julia was one down for most of the outward journey but had squared it by the 14th tee and it was a ding dong struggle after that, going all the way to the second extra hole before the World No 23 prevailed to earn a quarter-final tie against Sofie Nielsen (Denmark).
Engstrom actually won at the second extra hole with a bogey as she explained.
"Esther took two shots to come out of a bunker and I took three to get on the green, two-putting for a bogey 5 while Esther made 6," said Julia.
Engstrom now plays Nielsen for a place in the last four. Sweden had started the third round with five players still in the mix. But only Engstrom survives.
The last to go out was May Stark, beaten on the 18th green by Emilie Paltrinieri. It was a close match throughout with never more than a hole in it either way.
Paltrinieri now plays the No 2 seed, Norway's Madelene Stavnar who won by two holes against the 18th qualifier, Alexandra Forsterling (Germany) who reached the quarter-finals of this championship 12 months ago.
Both Stavnar and Forsterling led at different stages of the outward journey and Stavnar won the 10th hole to square the contest. The Norwegian edged again to be one up after 13 and hung on to her lead, doubling it by winning the 18th.