Penny's sleep update

Penny still wakes up once in the night. I (mom) had been waking up with her and feeding her thinking that she needed to eat to make up for not eating enough (milk) during the day. Dad has taken my place a few nights now and has gone in to comfort her when her crying doesn't seem like it will subside. It turns out that she doesn't really need to eat, but now he has started a new unsustainable habit. He checks on her, lays her back down and reassures her. Then, he stays in her room for a while because if he leaves, she starts crying again. Today I found his pillow and blanket on the floor in her room... how long will this last?