My mom watched LO this morning, and mentioned that she layed her in the spare bed to nap because she wouldn't sleep in her pack and play. She's 12 weeks old, and isn't rolling over yet, but I'm still not entirely comfortable with it. There's so much stuff out there now about where babies should and shouldn't sleep, and it's easy to worry. I will be the first to admit that I'm naturally a worrier anyways ,so how do you feel about babies sleeping on an adult matress?