This trope is when a LGBT teenager who is homeless is taken in off the streets by an LGBT couple. This is not the same as has two moms' (but can over lap) this is a story line when a gay, lesbian, bisexual or transgender youth who has become homeless due to various reasons has been taken in by a Gay, lesbian couple or a couple where one person is transgender.
Live Action Tv;
Queer as folk; Hunter who is ambiguously bi is taken in by Ben and Micheal
My so Called Life;camp gay teenager Ricky is taken in by his gay teacher and the teacher's partner after he is abandoned by his Aunt and Uncle.
Lesbian writer Cris Beam is the foster mother of a previously homeless transgender teen. She writes about her experinces with her foster daughter and other homeless trans girls in her non-fiction book 'Transparent'