Thanks for everyone's input!

Steph, your situation helps a lot since it sounds like what I want to happen at DD6's school.

Did you advocate alone or organize with other parents of GT children? What avenue did you use to keep the conversation going with the principal (PTA, individual meetings, etc.)?

I'm hoping DD6 will be in a full-time, self-contained gifted class the year after next at a different school. If it took two years, I may not be able to get any cluster grouping for her before then, but if I start now maybe something can happen for DD4 (or other children down the road).

Glad to hear it's working out well and it's encouraging to know there are success stories out there!