I use a similar theme with my main characters. During story background research, I discovered that many foster children and adopted children have an instinctive urge to seek their biological kin, even if the children have a great relationship with their host family.
For my characters, Freyja is technically an orphan (a clone with no traditional parents). Although saddened by her missing (or lack of) family, Freyja does not have any desire to seek distant / lost kin. Freyja’s subconscious identifies Dov as both a suitable substitute and a close friend.* One reason for her unquestioning loyalty and devotion towards him…Unknown to either character, Freyja was created with about 10% of the medically comatose Dov’s ‘borrowed’ DNA…Krista also helps a little when she ‘adopts’ Dov and Freyja into her inner circle. The end result of Krista becoming closer to her new housemates than she is to her parents.
*With Dov, you have more than most girls ~ Krista.
*A familiar touch is a potent asset ~ Dr Lander.
An interesting problem for my future chapters, should I ever get to them, is what will happen when Freyja meets the parents of Aivia, the deceased girl Freyja was cloned from. How will their genetic memories and unannounced familial bond influence that encounter?
I just remembered a story I encountered during random library browsing.
I found a book about US Military Working Dogs. There was an account of a dog-handler combat pair serving in Iraq. On one mission the handler was killed in a firefight. The Army soon determined the master-less dog was too violent and aggressive for retraining or pairing with another handler…Yes, this fur-missile scared the US military…The only option left was for the dog to be put-down. However, back in the US, the handler’s parents asked the Army if they could adopt the dog, to help manage their grief. The Army tentatively agreed and flew the Prozac-filled pooch back to the States. The bereaved parents and the now-retired military dog bonded on first sight, instinctively recognizing each other as belonging to the same family / pack. No one, except for uninvited house guests, had any further issues with the veteran pup.