NC as I regularly contribute to other threads on MN. Don't want this to be outing, but am very conscious of drip-feeding, so will do my best to give all the relevant information. I'm also very aware that this will turn into an essay, so apologies in advance.
DH has been no contact with his sister (my SiL) for around 18 months.
SiL has had alcohol related issues for a number of years.
She's been horrendously verbally abusive to all of us. She has made some horrendous and provably untrue allegations about her eldest brother (DBiL) which nearly cost him his job. She has had countless run-ins with the police. She has a criminal record for drugs offences, and countless other fines and warnings for anti-social behaviour. She has been known to turn up at DMiL's, DBiL's, or our previous property at all hours of the morning, hurling abuse through the letterbox until someone l calls the police.
She has previously been to rehab, and left after the first session on the first day. She has gone to therapy, to a psychologist, to AA... you name it, she has gone to it. But it hasn't made much difference. Recently things have been quiet with SiL, but that is only as she's recently lost her job and doesn't have the money to pay for her alcohol.
Anyway... the only person to have stood by her is her mother (my DMiL). She has been through the ringer with her, but has always done her best to support her. Sometimes this has meant she has enabled her behaviour, but she does her best.
Recently, DH and I moved into our first property together (previously in rental due to saving for good deposit). DH and I made it clear to DMiL that we were not happy with SiL knowing where we live, as we wanted a fresh start away from the drama. This is particularly important for DH, who has dealt with this for most of his life and it has severely affected his MH - he has anxiety, panic attacks, etc. - but is also important for me, as I've had to deal with a fair bit of stress caused by SiL over the years. There's just too much water under the bridge now, and SiL does not own or take any responsibility for her behaviour or the pain she has caused.
However, DMiL thinks we are being unfair. She has said that SiL is "better" and that being involved with decorating her house would be cathartic and "give her something to focus on" following her loss of employment. She has already gone against our express wishes by telling SiL about the house, but says she has not told her where it is. DMiL, who I have an absolutely amazing relationship with, has asked me to try and convince DH that it would be for the best to allow SiL back into his life. I refused, on the basis that it's his decision and his alone, and I would support him in whatever he needs / wants to do. It has caused a bit of a tiff, with DMiL unhappy and worried that by telling SiL about our wishes, she'll tip her over the edge again.
AIBU for not giving any ground here?
Whilst I don't think SiL being around will bring any good, I would never stop DH from having a relationship with her if that's what he wants.
If anyone has managed to get through the end of my version of War & Peace(!) and thinks they could put my mind at ease, I'm very appreciative in advance ❤️