I know some others here with females said they had issues with their little girls going potty after their spays also. Just keep on being diligent, treat her when she goes where you want her to go and praise her also. Jack will be 3 in May and just today he had an accident. Well either that or he was marking his territory...
even though he's been neutered... At any rate, hang in there and just keep a very watchful eye on her. As soon as she looks like she might start going potty, swoop her up and take her immediately where you want her to potty. She'll get the hang of it eventually.