Lauren is crawling and into everything. We had to lower her mattress. She was able to pull herself up on her knees using the top rail. But 3 nights ago, as I was trying to get her to sleep, she would not stay down – literally. When Mike came to check on us, she got so excited that she went from her knees to her feet. Mike and I both jumped toward her to keep her from falling. So Mike lowered the mattress on her crib. She still pulls up on her knees but she can’t stand up – yet.