A Place for Annie (movie, 1994)

Baby Annie is HIV positive and has been left in the clinic by her drug addicted mother. To prevent that she's deported to a home where they'd just wait for her to die, nurse Susan takes charge of Annie at her home. Two years later she plans too adopt her -- but suddenly Annie's mother reappears and demands her back. And under the law, Susan, as foster-mother, has no claim to the child.