DH and I co-sleep with DD (10 months old)...She's not a very sound sleeper. Usually when she wakes up she nurses for a few seconds and goes right back to sleep. Last night she woke and and I didn't wake up completely - somehow (instinct?) I startled myself awake and turned to just barely catch her about to crawl off the bed. Our bed is tall (4 ft), so she would definitely hurt herself if she fell. Any suggestions?