SIL messaged me after 10 YEARS

Helllooooo beautifuls! Happy New Year!

Last year I posted a lot about my garage dwelling MIL. My last post was that we were just going to move out. A lot of people asked why WE were going to be the ones to leave but things got too hectic and I never updated or responded.

We moved to a completely different city. Still close enough for my husband to travel to work, but far away enough that we knew my MIL wouldn't bother to ever want to come over or even look for us. We needed to do this for our own health. Being in the same suburb as her was too close. We made the necessary arrangements and we were able to leave with no problem. Where she is now, I don't know.

Her behaviour escalated when we were busy leaving and she basically threatened my husband's inheritance if he left... She showed him a bank account with close to 1m in it and told him if he stays with her, that money is his. Then after we left she conceded that she expected him to leave me and stay with her and that I'm this and that and all the other awful things she kept trying to get him to believe.

After we left, my husband and his sister touched base for the first time in years. My SIL also was not kind to me. She also tried to convince him not to marry me, also made as if I were the devil, etc. But with her own distance and therapy she seems to have turned a corner. My MIL has been telling people we abused her while she was with us. She was telling people I ignored her and treated her badly after mere days of being there, and that she had to hide in her room to hide from my abuse. She was telling my husband this, my SIL this. And who knows who else. My husband set my SIL straight, and the more they spoke between themselves the more they realised I have been right about their mom for decades - their mom is a horrible, manipulative piece of work. Neither of them have spoken to her since about a month after we moved out.

Having said that, my SIL sent me a message over the weekend that I haven't opened but I read it over preview. She basically apologized for being hurtful, their mom manipulated her into thinking I was awful, their mom had done a lot of things to hurt all three of us. She thanked me for standing by her brother all these years and would like to start again, because we're family.

I don't know how to reply to that. Yes she did things to hurt me. Yes I understand we are ALL victims of their moms behaviour. Yes I understand that she has grown and changed. But it's still a bit triggering to hear from her, you know? Last time I spoke to her was before our wedding when she was trying to bait me into giving her evidence to use against me to stop my wedding. I don't know how to reply to her.