That is a tough place to be as a mother.  It's hard for children with ADHD to make friends and maintain friendships b/c they usually can not concentrate(sp) on one thing long enough to play with the other children.  My daughter is now in first grade and she has ADD but also has narcolpsy.  I started a girl scout troop for her and the girls in her grade so she could do some fun activities with her friends but I am presents to help her stay focuses and have a good time.  I know this isn't an option for everyone but structured play dates can also help.  I've also noticed that kids this age tend to still do their own things more often than not.  I been lucky enough to see through the troop meetings that she isn't all that much different than the rest of the girls and only a couple of them have that true buddy the rest still float around.