Instant dislike

Oh gosh yes. Living with a lot of nuns might be really testing. You'd have to get on with all of them and there'd be bound to be some who grated on you - plus you'd have to be very good and holy!

It's said that our tummy, belly, abdomen, (delete as applicable, or scream at your phone) is our second brain.
When you rationalise not liking someone using your sensible old brain, your stomach steps in and gives you "gut feelings" instead.

I went onto the committee of a well known UK women's federation (!). I came off pretty pronto. 'This is what we have been doing since 1971 and will continue to do it our way....' They were constantly asking for new members but it was impossible to join because they were cemented in stone. The 'leader' of the pack was really very rude and dismissive and I thought 'I am driving out on a dark winter's night for seven miles to go to a meeting for what? To be put down or dismissed!'

Ooh a silent order hollysteers....I bet there's some withering looks.

I would say if your daughter has a position of authority within the school this woman is after it, and if not, she sees her as a threat to her ambitions.
Sound advice to say little to this woman and tokeep her own counsel, but watch her back.