Have posted before about BM contact for advise.
Around 8 years ago, I started to have contact with Bio Mother after many years of no contact. She chose to have me adopted due to being at college for context, however stayed with Bio Father and there then ensued a bit of a custody battle with adoptive parents (long story) which was very traumatic for me as a child. My childhood was very unhappy and I was not happy with adoptive family either, where there were other issues.
After I had DC, I started letter contact after resisting contact for many years (there was a lot of unwanted attempts at contact by them/their family).
Really I guess I should have predicted what would happen but I felt like I needed some peace and to stop avoiding feelings I needed to manage. After 2 years of letter contact BF died. A year later I arranged to meet BM, I had misgivings but wanted to see if there was a connection. I realised there isn't quite soon. But I have been continued to visit her every 1-2 months for a couple of hours as she is lonely etc and sometimes help her with house admin, get some shopping for her (I try to think of it as helping an elderly neighbour). My DC have met her several times but don't know who she is.
She isn't happy with the level of contact and at least twice a year I have to remind her of boundaries and the level of contact that I want and that I don't want to meet her family etc. I just try to be consistent and calm. She now expects my DC to visit and they really don't want to and I absolutely will not force them to, so generally just say they are busy which she is very unhappy about. Tbh I am gobsmacked at her level of entitlement - I had hoped she'd be happy with the occasional visit.
I am finding this all really difficult and almost at the point of cutting all contact.
Writing this all down it seems easy, but it isn't. It feels so complex emotionally. I guess I am a typical adopted child trying to please (but am resentful and angry too!)
An added note - financially she wants to provide for my DC when older at uni for example and has the ability to, so I don't want to disadvantage them because I am finding her too difficult.
She's really not supportive or that nice, to me which I find so hard to understand.
Sorry for huge post.