So, we've lowered Brighton's mattress since she started sitting up and pulling herself to her knees in it. We don't want any babies falling out of their crib! We were just going to lower it to the next one down, thinking that Brighton won't be pulling herself up to standing for a little while. I mean, she did JUST start crawling and pulling herself up onto her knees recently, she won't figure the standing up for a while yet. But, we decided we would just lower it all the way, so we wouldn't have to break out the tools all over again and deal with it. THE NEXT DAY she's pulling herself up to stand in it. Coincidence? I think she just needed the challenge to reach up a little higher. Needless to say, she's no longer sitting up to greet me when she wakes up. No, she's standing there waiting for me. And now she's pulling herself up onto the couch, the coffee table, and up the stairs. It's only been a few days! How does she figure this out so fast?