SIL has a moderate learning disability and long term health conditions, mid-forties. She is very naive and trusting. She has regular care and support but lives on her own. In the last few months she has met a man on a dating app (without a learning disability) who has just come out of prison, multiple convictions of very serious violence and harrassment. SIL knows about his conviction and but says he has changed. SIL is travelling many miles to stay with him for most of the week in his halfway house accomodation that he rarely leaves because he has restriction orders placed on him. There are already signs of coercive control, he doesn't want her speaking to her family, asks her to bring him food, phoned her thousands of time when she was in hospital for 3 weeks from complications relating to infections he had given her. He also moved in with her for several weeks until the police found him and took him back (and then placed a restriction order on him from the town where she lives). Apparently nothing can be done at his end until he harms her.
My question is about safeguarding. SIL's main care worker is stressing her automony and freedom to make decisions. But I think she is at serious risk of harm because she is increasinly being isolated by him, i.e. undue influence and pressure. SIL has no friends, only her very frail mother in her eighties and her brother. SIL's health is increasingly poor too, she's in constant pain, in and out of hospital etc. She however is going willingly to see him and says she loves him.
Her brother is considering raising a safeguarding concern. If he does, what should he say on the form to get someone to protect her? We all think it's now time for her to go into care because of her vulnerability. It's not the first time she has been targeted. I'd appreciate any advice from anyone who understands the system.