At 18 mo my daughter's crib lost its front wall, and at 22 mo she moved to a twin bed (frame is solid with built-in drawers beneath--no crawling space) plus a stool to get up onto it. (We would've waited on the twin bed, but since we moved house then, it seemed easier to get the transition over with.) Till she was ~2.5 yrs, she waited to have us come and get her, though granted, at first she was a younger child than the Junebug is and it may've made her relatively tentative. Now she peeks around the doorway to look for me, and if she can't see me immediately, she seeks me or darkforge, not mischief. She'll be three within two weeks.

We had a baby gate keeping her out of our room at the old condo (unprotected bookshelves and a desire for me to sleep while I could sleep), but otherwise, since I'm a light sleeper (darkforge is not!), I figured that I'd be able to hear most perils. Much depends upon child personality. The "new" house is only minimally childproofed since move-in: chemicals under the kitchen sink under childproof lock, but other things are only moderately up out of reach--enough that her climbing up would make enough noise to wake me. It's a small house, and she understands both that knives can hurt her and that her parents would be very upset if she cut stuff up randomly. I am guessing that Something will happen within ages 3-5, but 2-3 has been totally fine....