Received a friend request on fb from exes girlfriend

[Mumanddadtoone]

Hi, I split with my ex 18 months ago, he left to go to other woman and she has since had his baby. I don't speak to ex at all even though we have a 5 yo ds with non verbal autism. I stopped him seeing ds 9 months ago when it became obvious my ds wasn't safe with him (ex fell asleep whilst 'looking after' ds and on other occasions took him to the pub where he was taking cocaine).
Ex contacted a solicitor a few months ago and I was asked to attend a mediation appointment to check if we were suitable for mediation. The mediator didn't think mediation would help and that was the last I heard from him.

Today, though I get a friend request from his gf. He knows I can't stand her so I'm unsure as to why she would send the request. I have declined it and blocked her from contacting me again.
Did I do the right thing? What would you do? Could it have been sent accidentally (obviously if she was looking at my page)?
Sorry, I know this isn't a big problem and some of you are dealing with real dilemmas and heartbreak but I don't really have anyone I can ask in real life and tbh I'm really curious as to why she would want to befriend me.
Thanks for reading

I imagine she was looking at your profile and did it by mistake.

I have sent a friend request by accident before when Facebooking on a mobile phone so it can be done, if you are nosing at someone's page. Or even if you aren't - I think I meant to press like on someone's comment on a friend's page and ended up sending the guy a friend request instead. So it is possible.

God, she's got herself a real prize, hasn't she? I would have thought she wants sympathy from you now, because he's doing the same to her as he did to you.

Perhaps she wanted to ask you questions about him...?

I think you did the right thing by blocking, you don't need her as a 'friend'.

I think you probably know the answer to that one. Maybe she's suffering with your ex and wants to talk to you about it?

Thanks for the replies, it probably was an accident or she's suffering with him. I know they fight a lot and he disappears for weekends at a time (not with other women, just taking drugs and drinking) (didn't mean JUST as if it's nothing!!!). Well she's blocked so hopefully that will be the end of it.
Thanks again

I've had quite a few xxxx accepted your friend request.

Yeah, best to block her.

Yes whatever the problem its not yours.

God, you should be thanking your lucky stars you offloaded that waste of space, well done in looking out for your child.
You absolutely did the right thing in blocking her, doesn't matter how or why you received the request, she is of no concern to you.
You really did dodge a bullet with your ex.