Attachment After Adoption

I have not had any problems attaching or bonding with the child my husband and I just adopted, but I do have a certain family member who is hesitant to bond with him because the adoption is not "finalized". The birth mom has already consented to terminating her rights and from my conversation with our adoption attorney, the only thing that could change the adoption is if they believe the child is being abused. I tried to explain this to my family member who is having a difficult time, but she is still recommending for me to not get too attached so I don't get hurt if the adoption falls through. I am very confident everything is going to continue going well with our adoption and I want all of my family to love and accept my son. Has anyone else had experiences like this and if so, how did you calm the worries of concerned family members?