How to respond to father in law's partner's rudeness?

[RareRuby]

Hi,long term lurker,so please be kind!
My mother in law passed a few years ago and my father in law who I am very fond of has in the last 2 years met a new lady friend,they don't live together but spend holidays and some evenings together.
At first I was pleased he had met someone but now,I'm not so sure and I don't like her very much.
Examples are-she doesn't like his long time friend-for no reason,she's just not keen.
She has interfered about times he has helped out with our kids by needing a lift somewhere-she also drives and has a car.
She said my brother-in-law was ignorant,the first time she met him-he really isn't an ignorant person.
Doesn't like photos of my mother in law being up in his house.
They argue quite a lot-usually over things that she isn't happy about or if he refuses to do as she wishes.
She has been blatantly rude to me on several occasions and I've just given up speaking to her now directly.
And to add,no one is perfect but I don't think I can take much more of her sly digs and cheeky comments...so mumsnetters,short of causing a family war-how do I avoid upsetting father in law by being honest about how I feel?

Does DFIL hear her being rude to you? If so you could tell him afterwards that you found it upsetting and ask him what he thinks about it. You and DH could tell him you’re both worried that she is making him (DFIL) unhappy. But really this is an issue that would be better left to DH to discuss with his father.

Can’t you just pull her up on it at the time?

The only one of these things that has anything to do with you is if she’s rude to you. Then, as a pp said, pull her up on it at the time. Whether she doesn’t like your FIL’s friend or thinks your BIL is ignorant, or doesn’t want photos of his dead wife in the house or whether they argue are none of your affair. You don’t have to like her, or to ‘be honest’ with FIL.

How much contact do you have with her?
Because if she is rude to you I would be not accepting invitations if she is there and if your H invites her to your home I would be busy else where.
It's up to your H what he does.
And up to your FiL if he wishes to continue his relationship with this woman.

This is not a battle you can win. I agree with @InAHammock . She does sound like a fool though, sympathies.

This is an issue for your husband to deal with, not you.

He needs to be the one to approach his father and point out all of these issues.

Your FIL might be in a bit of denial and having someone mention it to him could pull his head out of the sand.

Being rude to your face is one thing, but the rest is none of your business and you shouldn’t be getting involved. If your DH has a problem, he can raise it with his father and sort it out. Otherwise it’s nothing to do with you.

Agree too, it's likely she's trying to push your buttons so will be happy if you don't go to FIL house or make scarce at yours!

I'd she's rude to you, tell her at the time that she's being rude. The rest of it is none of your business and for your FIL to address. If he chooses to put up with it, that's up to him

What is she like with the rest of the family and what do they think of her?