Need some perspective

So...this is going to be long. I’ve not posted here in a long time but I lurk from time to time :) The short version is this: We adopted the daughter of a childhood acquaintance of mine in 2014. Her birth mother and father are very mentally ill. It is an open adoption. I believe in people knowing where they come from. In the agreement it states that of my daughter doesn’t want to see them she does not have to. For the last 4 years she has wanted to go, but this year she has declined and I have honored that. I have seen unprecedented growth and maturity in her since we have stopped contact. In January her birth father became very ill. Her birth mother has significant menta illness and it is difficult to determine what is truth and what is “baiting” me to try to engage with her outside of what has had to become very strict boundaries. But it seems as though her birth father may be truly dying. It is also important to note that her birth father is one of her abusers. Her birth mother is becoming increasingly insistent that I allow my daughter to have contact with her birth father before he dies. Everyone in our family and friends cannot be objective here so I am looking to strangers for some perspective. I am extremely uncomfortable encouraging my 6 year old to see someone who 1) she continues to decline to see, 2) was her primary abuser; 3) who is in a serious state of illness and I am fearful of her becoming alarmed by his condition; 4) all for a person she doesn’t have a connection with and doesn’t have a relationship with at this point in her life. However. The flip side is that he is her biological father. And if he really is dying, do I deprive her of that last contact? I am so torn. Anybody have any brilliant nuggets of advice? I really appreciate your kindness. 💜