J.L.
When my first was not even 14 mos she was doing the same as your 21 month old fighting agaisnt the nap. It was one of those days. I put her in bed she stood up screaming and was trying to climb out. I looked at her and said there is no way you can get out. Went out, shut the door, went downstairs, sat on the couch, put my face in my hands and THUDD! SHREEEK! I fly up the stair to be greeted by my screaming baby at the door. I scooped her up, ran down stairs and called my mom. I tried to get her to walk but she wouldn't. I called my ped. who said to bring her in and that he would wait to go to lunch. So we flew to the doctors office and thank goodness she was fine. (we think it was just the initial shock that she couldn't walk in the beginning because at the doctors office she was running.)But my doc said we were lucky. She had to be done with the crib. Thankfully we had bought the convertable crib so we just took the big side rail off and she was fine. If you do not have a convertable crib buy a single twin mattress and mattress rails. (if you get a set save the box spring for later when she is older.) she will be low to the floor but not on the floor. Doc said not to put the mattress on the floor because bugs would get in the mattress, yuck. I was worried about her falling out but she never did. Now I have a 21 month old as you do. She is still in the full crib and makes fake attempts to climb out but really is not close. I always used bumper pads but we took those out now that she tries to climb. (I think that is what helped #1) She seems so little to me to not be in the full crib, too. Even though she is 7 months older, SO I completely emphathize. I don't want to say move her but I would not want her to get hurt either. If she knows how to escape the pack and play I sure she will figure out the crib very soon. My first only used the "convertable crib toddler bed" for a year so I definately think that getting a toddler bed is a waste of money. Good luck with your little one.