I'd opt for "Begindergarten" or "Headstart"... now days kids have to know how to write their name, address & phone number, know their colors & A,B,C's and count to 50 before kindergarten...
AND it is more than just knowledge.. is she psychologically ahead?? does she "act" and "Behave" older than 4?
What about socially? Is she very social with large groups of kids? or does she stand apart and observe?
All of these things have to be considered for HER sake...
and then again-- no matter what the answer to any of these, it depends on the standards where you live...
When we moved to where we live, despite the fact my son was reading at a 3rd grade level, doing Math etc... they would not let him into Kindergarten until age 5... and THEN we still had to hold him back due to socialization issues (He is an Aspie)