Phoebe got tired of standing around. She was almost always standing. Sometimes she'd lean against the wall or use the doll stand to break up the monotony of standing. If she wanted to sit, she had to sit on the floor, which isn't bad for a kid ... for small amounts of time.
But a nice fat cushy arm chair is much more comfortable. So comfortable, she could even nap in it if she wanted.
A line of bright fun doll chairs and quilts to be for sale soon on Etsy. After all, your doll sometimes just wants to chill.