do you think saying a pet is family devalues actual family members who are blood relatives?

do you think saying that a pet is family devalues your blood relatives? I hate when people say their pets are family, my dad says our cat is my sister and I hate it. If I die I hope they will cry a lot more then if this cat dies.I dont want it to die but if one of us had to die I would rather it be the cat then me. I love cats though, I would be very sad and upset for a long time if she died.