You can use the SBV in younger ages (normed beginning at 2 I think), but to be honest, I don't believe there are any accurate tests for a 3 yo or 4 yo. Why do you need to test?
Unless you need the information for some specific program or plan, I think you'd get more for your money at 6 or older.
thanks everyone. I don't really need her tested, it was partially out of curiosity, but also for school planning. She already hides things--pretends to not be able to read around her classmates sometimes, uses a different vocabulary around children her own age, etc. and I am trying to figure out what to do for her this year and next. As of this moment, she is going to a very slow paced play preschool next year then to a two hour a day slow paced kindergarten. This may work, but only time will tell.