Is this projection and how do you deal with it?

Several months ago, my relationship with my younger sister disintegrated. She had phoned me one evening and then started complaining about mum. Mum (early 70's) is going slightly deaf. My sister said she ought to get hearing aids. I agreed that it might be helpful, but said it was really Mum's decision. She disagreed and accused Mum of not getting hearing aids because she didn't want to listen to her (which I thought was a bit extreme.....she is only slightly deaf). Then she started attacking Mum over other things, accusing her of not respecting her time and being "needy". Yet it was my sister phoning Mum during lockdown and keeping her on the phone for an hour each night, complaining about her problems with work, neighbours etc. I know she does that, because she used to do it with me. And like I used to do, Mum keeps trying to make suggestions when my sister pours out her woes....but apparently that is us both "telling her what to do". She doesn't seem to be able to distinguish between a suggestion (which to my mind is what people do when you keep telling them over and over about your unresolved problems) and someone "telling her what to do". Then I got the whole Covid thing. Mum and I had been meeting for a walk once a week in a public place...and my sister didn't think that was responsible. My mum lives alone, it was within the rules, and again, it was Mum's choice. I've never heard my sister go on the way she did that night on the phone, but it was almost like years of resentment that had been bottled up was being poured over Mum and I.

My sister has had numerous failed relationships and wherever she goes or whatever she does, she has problems. We did have a very controlling, emotionally (and occasionally physically) abusive father and I've put many of her troubles over the years down to low self esteem. Because of the way Dad treated us, I’ve always felt very protective of both my sister and my mother and would do anything to help either of them. I’ve helped my sister out financially (she still owes me £6k), helped her out practically and even gave her a termporary job (I run a business) when she moved to live closer to us when she made the decision to leave her then partner and was out of work at the time. My mother goes running to her to help out at the drop of a hat…..but on the phone that night, she turned the tables again. Apparently, mum and I “treat her like a charity case”, which is pretty hurtful. Of course, we offer help and support. That’s what you do when you love someone…..and she’s never refused that help, or even hinted before that it wasn’t appreciated.

Then she brought up Christmas. I usually invite her and mum to us. I’ve done this every year since my boys were little. Except when she’s been in a relationship and has made other plans, she usually accepts the invitation. Now, she is accusing me of not respecting that she might want to spend Christmas on her own! Yet, I’ve never pushed the invitatio and have always respected her answer. I’m not a mindreader. If someone accepts an invitation with not a hint of hesitation, how am I supposed to know that they don't really want to? And is it my fault for asking or hers for not giving me an honest answer?

We had both been astranged from our controlling father for some 15 years (mum had eventually summoned the courage to divorce him) but in what turned out to be the last year of his life, his health deteriorated.. I made the decision to go and see him because we had word from family that needed help. Social services were looking for family intervention and to be honest, I also wanted closure. My sister was more hesitant, but she came along with me on that first visit because she said she wanted to support me. Social services wanted us to find him a nursing home (difficult because he was local authority funded). My sister didn’t drive at the time and we decided that it would be best if he came to a nursing home near me. She didn’t visit him again until the hours before he died, but I completely accepted this. He was a difficult man and I respected that this could open old wounds for her. Dad owed money and his bank account had been frozen since he lacked mental capacity. Social services wanted us to sort his affairs out (which I did….and sorted everything out also after he died). Although we both work full time, she never offered to help, and again I never complained or asked her to. At the time, she would say “I feel bad that I haven’t got the time to help you” and I would reassure her and tell her it was okay. My sister always seems to have problems, and because I’m protective of her, I wouldn’t have dreamt of asking her to take on further headaches. But now it seems she has also suddenly decided to project her guilt for not doing anything and blame it on me for “making her feel guilty”.

It seems that everything I have ever done for her (and it has been very one sided) has been twisted. She’s accused me of being the “favourite child”. I suspect that lockdown has affected her mental health, but I haven’t contacted her since our exchange because if she feels so badly about me, quite honestly, I’d be overanalysing my every word in case it could be misinterpreted.

She sent a Christmas card at Christmas after she’d hurled all of these accusations at me as if it had never happened. Mum has just accepted her abuse and has not mentioned it since. but I’m struggling to do the same. I know Mum wants me to because after all we’ve been through together, she doesn’t want to see a rift between her daughters. But how can I sweep all of this under the carpet and pretend it never happened? How do you rebuild a relationship when someone assassinates your character to twist everything you’ve ever done for them over the years out of love into something bad?