mother-child fostering

i am applying to foster a teenager. i decided a teenager made sense because by the time i'm ready to go to a convent the child will have aged out of foster care. one of the options with a teenager is a teen in foster care who has had a baby. it's called mother-child fostering.
i went to my first class on parenting a foster child. i have to complete 30 hours of training. i was the only white person out of 21 participants. almost everyone else had fostered unofficially (family members and their kids' friends) or officially. is it a cultural thing that white people don't do foster so much? i felt like i was representing god's frozen people.
i have so many concerns, worries, and fears around this that i have decided to turn over each step along the path towards fostering to god. first i have to take these classes. i have to get certified and licensed and that requires multiple steps. i will just keep turning it over.
what if the child is so angry that she is violent with me, my dog, or my rabbit?
what if she abandons her baby with me and runs away?
what if she hates me and is mean?
what if my race, neighborhood, culture is all too white for her and she is miserable?

i am trying to think also what if we make a happy family? what if she's scared? what if she's gentle and shy? what if she's vulnerable and needs help? what if she's happy here? i'm trying to imagine that. happy families with teen, baby, puppy, bunny, backyard, park, school, church.