N.J.
I have six year old twins that have shared a bed since they were about 3. My girls would get up in the middle of the night and crawl in bed with me too. When my husband was deployed I didn't care. I was and still am a stay at home mom. I did everything you did, and sometimes it would work and sometimes it wouldn't. So I ended up putting up a gate in the doorway. That way if they got up, they wouldn't wonder around the house and get into anything, and wouldn't crawl into my bed. I could still hear them, and got up to do the potty thing, but they went right back to bed afterwards. I'm a supper nanny fan too. :) Hope this helps a little.