A gets special treats after labs, procedures, etc. Usually something simple like going out for ice cream or letting her pick a spot for lunch.
But I also have to be careful that my other daughter doesn't get jealous of the extra attention A gets. So M and I have taken up baking together. It is a way for us to spend time together doing something she enjoys (baking isn't my favorite thing in the world but she likes it) and then we can share the finished product with the family. It is "our thing" and that makes her feel special too.