When my daughter was 1 and a 1/2 I brought her to see her mother for a family visit. That was mom's first stint and I thought it would give her hope.
Now, having dealt with 4 additional stints over the years I have not once brought my daughter to visit and feel that it's highly inappropriate.
My daughter is 5 now. She's like a sponge. Visiting institutions is not something I want as a norm for her. Children are impressionable and her repeatedly visiting mom could give her the impression that rehabs are a "normal" part of life.