There is, however, a comment from the stepmother (bio dads wife) in this article here:
Tatiana Wallace, Madeline's step mother, also spoke out about the young girl's disappearance and Sterns' recent arrest.
'My stepdaughter Madeline has been missing for more than 72 hours. With Stephan Sterns behind bars, we can concentrate on finding her. Share her photo with everyone you know,' she said.
Edited by me: messed up the link. Still learning the interface, sorry.
Edited again: I give up on the link, sorry again!