Does she have a cot, Kate? At 12 months, you may do better to just take the drop side off the cot altogether, so you essentially have a sitter bed. This way they will not feel so caged in, there is nothing to climb out over, but the bedspace itself is still comfortingly smaller.
Then you can continue to do exactly as you do now, just with the side off.

This is the first night with the side off at our place when we went in to check on her. She is still sound asleep in this pic, and did not wake when we moved her back into the bed... Alexis Photos | Facebook

So she was on a pillow, a very flat one, and we put a second pillow lengthways down the outside of the cot. We have never used a cot rail or anything. And she has a cot doona.

HTH