Luisa Maria is a character on the "show within a show" Prescription Passion. She is played by actress Dina Defterios.
House is watching the show in Games and notes that Luisa Maria can't decide whether or not to keep her quadruplets while she fights with her older son Chris. She threatens to leave him.
In No More Mr. Nice Guy, she discusses with Dr. Brock Sterling how he's going to leave Marie for Anna.