Earlier in the movie mom (Betty) gets her first finger on her right hand cut off by GM.

At the end, ther is a bake sale out front of the Bakery and two little boys ask if they have any gingerbread man cookies. Betty puts her hand on one of the boys shoulders and you can clearly see (in close up)that she has her finger bent. Then, in a shot to include everyone and the front of the Bakery, she doesn't even bother to hide it and you can see her "missing" finger extended normally.