Sierra learned to climb our stairs yesterday. I was totally unprepared for it and shocked. I had quick run upstairs to hang up some clothes in Simon's room and was gone for about 1 minute and I came out of his room and Sierra was on STAIR THREE. I kind of freaked but didn't want to run down the stairs at her in case she freaked and backed up and fell down them all. She was fine and crawled up and down them all day? What Next?