A rocky road

I am a divorced mom of a Multiracial family. Both my son,9 and daugher 8 have contact with their birthmoms. Unfortunately their dad has chosen not to be part of their lives since the divorce. My son's birthfamily lives nearby and he has a very relaxed relationship with them. My daughter tends to think life would be better if she lived with her birthmom. She doesn't understand why her birthmom made an adoption plan for her and not for other siblings. I have suggested she write a letter and explain how she feels. My daughter's birthfamily lives in the southern part of the state and I try to make a trip at least once a year. We stay with friends and plan an outing with my daughter's birthfamily which includes three siblings, older and younger. Last week we made our annual trip and much to our dismay, we were unable to contact my daughter's birthmom. I know in my heart, that she is upset about not seeing her birthfamily but she directs her anger toward me. I am just a mom doing the best I can. I know she is dealing with so many losses, and counseling is already a part of our lives. Anyone else have similar experiences and how did you deal with them?