Caleb has this one, And he loves it so much. It usually always gets him to sleep. Its light up in blue with a water fall. The sounds it so usual and soothing.
Fisher Price Rainforest Peek-a-Boo Waterfall Soother
He also has a hanging mobile, that show clouds that light up on the ceiling. It helps with the restless nights. And it goes on for a while and has a remote control with it.
Fisher Price Rainforest Dreams Cot Mobile
Posh if you lower the mattress down it should be ok. With the tv one thats in my link. It hangs tight on the cot. Baby cant get it off. Its actually hard for adults to put it on. But thats the whole idea. So it cant hurt baby. And it not to late for to get one for her. It might actually help her go down during the day in her crib.
Alot of the times, Babies get bored, and thats why they dont want to be in their crib alot of the times. Its worth a try
I switch between the 2 at different times, Just so he doesn't get bored with the one.