Open adoption question!

I am a momma to 4 kiddos through the gift of adoption. We are also a transracial adoptive family. My husband and I are white and two of our children are black and the other two are white. My second kiddo was placed with us when she was 7 months old. She was severely neglected and starved before her removal of the home she lived in. Also, birth mom used substances while pregnant with her and our daughter was born with drugs in her system. She is now 3 1/2 years old and thriving! We love her dearly! Our daughter is a birth sibling set of 5 kiddos. All kids have been parented by maternal grandmother with the exception of our daughter who we adopted when she was 7 months old. We now have one of her birth siblings living in our home with plans of adopting her as well. She is 14 years old. We also have our son (who we adopted at birth) who is 6 years old and our youngest daughter (who we are about to finalize her adoption) who is 1 year old. We have open adoptions with all of our children's birth families (when it's healthy- for example no drugs, no gang activity etc...) and we are strong advocates for open adoptions when it doesn't cause harm to our children! My question is this: When we are around our two daughter's birth family (which is pretty often) they are constantly comparing our youngest (who we have had since she was 7 months old and went through hell and back before placement by drug abuse by birth mom while pregnant and then neglect and starvation by birth dad's family) to various members in her birth family- example: birth siblings, birth mom and birth dad. I mean like every time we see them they say that she reminds them of someone in their family...over and over. I am afraid this is going to cause a deep sense of longing within her little heart that causes her to feel out of place within our family unit. I am also afraid it will make my other adopted children feel a sense of loss because they don't get the same things said to them. My husband and I work really hard to make all of our children feel secure within our family and loved unconditionally. We are a transracial adoptive family and we don't constantly highlight our differences and we celebrate our similarities and I feel that this particular birth family is doing that by constantly telling our daughter that she looks just like so and so or laughs just like so and so...but maybe I am wrong?!? I would appreciate any feedback! Thanks!