Is this a ridiculous idea?

[grecianurn82]

I've been in a relationship with a woman (I'm also f) for 3 years now. Gf lives with her parents and dd. Gf mother is emotionally abusive towards her, very manipulative. Stops her having any sort of life outside work and home. Gf has fragile mh and can't seem to stand up to her. Over the last year her mums control has got worse to the point that gf and I only see each other an hour a week during her lunch break from work. I have been as understanding as I can but I've reached a point where as much as I love her, I can't do this any more.
My absolute last attempt to fix the relationship is this, but I don't know if its a really stupid idea. Gf has a sister I have never met. Next week I'll be in the town where she works for a meeting and I was thinking of messaging her and asking to meet for a chat. I basically want to explain the situation to her and ask if she could kind of mediate between gf and her mum to resolve this a bit. I understand she may not want to get involved which I totally respect, but the whole thing is getting ridiculous. I suspect gfs mums MH may be deteriorating which may be adding to the abuse. Oh i don't know any more. Part of me just wants to give up and walk away but I'm genuinely concerned for gf and her child in this situation as well.

I absolutely wouldn’t do that without your gf’s knowledge, no

Oh sorry I actually should have made that clear, I would check with gf beforehand and only do it if she was ok with it. She has a good relationship with her sister so inthink she might be.

If your gf is ok with it, I would meet the sister for a chat.
She may be able to give you a better insight into what's going on.
It doesn't sound like you're in a healthy relationship, and whilst I understand your concern for the gf and her child, it's not really up to you to solve it. In fact, it usually ends in tears.

I hate to be cynical, but if this post was about a man who was supposedly living with an abusive parent/ex, we'd all assume he was lying. I mean, you're not really in a relationship with this woman if you see her once a week, for an hour, in secret? Are you 100% sure you're getting the full story?

Of course, it's perfectly possible that she has MH issues, as does her mother, but this sounds extreme enough that if it's real, I'm struggling to believe her sister doesn't already know?

I'm also not convinced that your GF will agree to let you see/speak to her sister.

Thanks, yeah thats what I'm hoping. I kind of get the dynamics of it having been in an abusive relationship myself, but i just kind of feel like I'm missing something.

@Triffid1 yes I totally see why it could look like shes not telling the truth. I have a relative who would know the family quite well though who has basically confirmed to me that the mother is hugely controlling. There is also an element here that she will always been against this relationship due to it being same sex.

If she has a good relationship with her sister, why would a request for her to mediate between your GF and her mum be any better coming from you than your GF?