Hi E.,
You've received some great advice! Like many others, I would not suggest the tent. Given time and watching you open and close it she'll learn just as quickly how to open it.
All of mine (6) learned how to get out of their cribs. It just happens. With my first one, and this worked well for all of them, we established a bedtime ritual. Once upgraded to the toddler bed, we had a talk about being a big girl/boy and what it meant for her/him. So our bedtime ritual went a little something like this: Her bath always came right before bed to relax and calm her a bit from the days events. I would take her into her room, let her pick out her pj's (made her feel like a big girl :) & a bedtime story, (I can still recite the Animals On The Farm), dim the lights (small lamp or night light if it gives off enough light to read), tuck her into her bed with all the essentials (animal, blanket, or any other must haves @ bedtime, so there wouldn't be any reason for her to get up), read the story to her (sometimes 2 or 3 times to relieve any anxiety she may feel about this new step), we'd share our special kisses and I'd again praise her for sleeping in her big girl bed. I'd reassure her and tell her what I was going to do next (i.e.-I'm going into the living room with daddy or the kitchen to do dishes) so she'd know where I was IN the house and also let her know that I'd come back in a few minutes to check on her. This really helped! She was always so proud when I came back and she was still in her bed. I wouldn't say anything, but I'd give a thumbs up & a smile, so she'd see how proud I was of her for her "big girl" behavior. After about 2 weeks, she'd be asleep before the story was over.
Don't get me wrong, she'd get up sometimes, but I think it was a matter of self reassurance that I was indeed where I said I would be. I would either direct or escort her back to bed & gently remind her that it was night night time and mommy would be going night night in her big girl bed soon too. Then she'd tell me, "I'm a big girl like you, Mommy. I have a big girl bed, too!" It made her feel proud!
I, personally, never used gates or punishment for her getting out of bed as I feel the more relaxed and calm they are (and myself) the less it took to get them back in bed. Tears and an upset mom would only make the process take longer. As many have said, kids will take negative attention if it means their getting attention. Personally, I just never wanted them to feel like naptime or bedtime was a punishment. It is another stepping stone in their lives to move out of the crib.
Someone else mentioned, staying where you can be seen. I did this with one, because she wasn't quite as confident. I'd take a chair into the hall outside her door where she could see me and read my own book. We didn't talk, but it gave her the extra sense of security she needed to adjust.
Best of luck!
J. F.
Helping Moms Work From Home
http://www.4MeAndMom.com