I think a good starting point is to think of Christ on the cross whenever you get a feeling of hatred: He loved her enough to die for her. He is omniscient.

If He can love people we hate enough to die for them, shouldn't we at least refrain from hating them?

I'm sure she is a really annoying person, I'm sorry. There must be good points to her though. Try to find those, maybe meditate on them if she's lecturing on you, try to apply them to yourself if you don't already have them. Think of her bad points possibly and see how you might have them yourself, (if you do) and if you don't see how you can avoid them.

"Don't say: 'That person gets on my nerves.' Think: 'That person sanctifies me.'" - St. Josemaria Escriva

What she does sounds really really annoying, but if you tolerate it and pray for her, you will become saintly. Many Saints have dealt with annoying or terrible people and gained from it.

Sorry if this is preachy. I know I fail at this pretty consistently. Just trying to give what I've read though. :/