Holly lives, altogether, with five and a half sets of foster parents. The Kreuks count as half because they split her assistance check and lie to the caseworker, and for eight glorious months she is Rowan’s daughter.
Rowan can’t adopt Holly because she’s poor, with a history of suicidal depression and (not coincidentally) breast cancer. Holly doesn’t learn this until she goes looking. She gets extra-nice for a while, and Rowan figures it out, and they fight.
I’m not going to tell you they never get a chance to make up. They do. They make up in plenty of time.