I really am at the end of my tether with my SIL. This is been bubbling away for years now but I really can't cope any more with her passive aggressive nature and jealousy towards me and mine and my mothers relationship.
As an example - Pre lockdown she has visibly sulked before when she's found out I've popped to my Mums for dinner. I live in the next street to my mum and she lives 25 miles away. This has happened quite a few times. My mum has her eldest twice a week and I would sometimes pop in for lunch while driving about for work to see my niece and she would always ask her (at the age of 1.5) if she had seen me that day even if I hadn't been. It got to the point where me and my mum felt like we couldn't tell her if we had seen each other.
When lockdown started she made several passive aggressive remarks to both me and my mum such as 'at least you can still see your mum' and to my mum 'at least you can still see (my kids)' even though we actually hadn't seen each other at all.
I feel like she always pits herself in competition with me as well. I have learned as I have got older not to bite and will actively ignore parts of her messages where I feel like she is attempting to create competition however this is having no effect in stopping her from doing so.
She will ask what I have got other family members for Christmas/Birthdays then try and trump me. The most recent one really upset me as I bought a sentimental present for my grandfather who I have a close relationship with and after persisting asking I told her what I had bought. Within half an hour she messaged me asking if I had any pictures of my dead grandmother. I know whatever the present would have been if there was a picture of my grandmother then my grandfather would find that upsetting as his grieving journey has been a very private and personal matter for him. It was clear she was attempting to 'out-do' me.
I think deep down she is a very unhappy person and I do have a level of sympathy for her but I just don't think I can deal with it anymore. This lockdown it has been constant, almost daily, of her contacting me about xyz and always something passive aggressive said.
I want to cut her out of my life however know that's not really an option due to my nieces and the risk of upsetting other family members but I really find myself quite angry every interaction we have and it's starting to impact my mental health. I do not respond in an angry/passive aggressive manner and ignore comments she makes however it's so persistent it's dragging down. It's been ongoing for so long I feel like it's too late to assert boundaries and the passive aggressive nature of her interactions make it difficult to call out as she could very easily make herself look like a victim.
She's not well liked amongst my siblings and parents as her behaviour extends to pretty much everyone but this makes it worse for me as I feel like someone or me is constantly moaning about her which also drags me down.
I don't really know how to come to peace with her, I guess as I can't cut her out I need advice on how to cope with what happens and not let it faze me? Or is there something I should say to her in a diplomatic way?