It started last week when I was watching Mason. Jalyn came with Elissa to pick him up, and when she was here, she used the bathroom. Claire asked me where Jalyn went, and I said "Jalyn is going potty on the toilet, because she is a big girl", and I swear I saw the lightbulb go on in Claire's head. Since then, she's been wearing underwear (just like Jalyn) and going potty on the toilet (just like Jalyn). She had one accident since Friday, due to the fact that she was playing computer games and couldn't quite tear herself away in time. But otherwise she's perfect. We've even made a few trips to the store and to Jalyn's house without a problem.
And so, because she is a big girl now, I took the front off of her crib and she adores the new freedom. Now she has a "big girl bed, just like Jalyn". She only fell out one time last night, and immediately wanted to go back to sleep in her big girl bed. I didn't plan it, but its worked out really well because Claire has put the two things together. Going potty in the toilet means a big girl bed. Its good motivation. And having a 4 year-old friend that Claire idolizes is really wonderful.