what is your daughter yelling about? Has anyone explained that your fiance isn't trying to take the place of her mother? She may just be scared that this woman is trying to replace her mom or even trying to take you away from her. Also, what are the repercussions when she doesn't treat people well? She shouldn't be allowed to treat anyone that way and if she's used to getting attention for it (even negative attention) and your daughter is ignoring her, that could just be aggravating her more.

It is really hard when you come into a relationship and your new 10 year old doesn't like you. I have been a mom for 25 years and when I became the foster parent for my partner's niece (10) & nephew (9) it almost ended our relationship. My nephew is autistic and difficult to say the least - but my niece was where I had the problem. Our therapist said it would be harder on me because being a mom when I give love I expect love back and for some kids there are attachments issues that come up. It wasn't her fault - and 2 years later we are much better - but I can honestly say one of the hardest things I have ever gone through. Ask your fiance to give it time and take baby steps. There is a great book - "attaching in adoption" that has hints on attaching to a child that may not even want to attach to you. NOT just for adoptive parents - great for any child on the spectrum! So many great stories and things to think about.

Has your fiance tried bondng with your daughter?
If not try that. I don't know your situation, but trust is a big factor with many kids and autism. My son and my fiance didn't used to get along to well. but some of it was my fiance's fault. He took some parenting classes on parenting a special needs child and started working better with my son and he sarted being more understanding and acceptance to my son. Their relationship has came a long way from where it used to be.