the younger you test, the more unreliable the tests can be. The kids are just too little and so many things can happen. I would wait until she is at lest 4. You will get more information from the other subtests.
Is there any particular reason you'd be testing her? Local gifted schools don't even take results from kids under 4, too unreliable. Most of them prefer for the kids to be at least 4 yrs. 6 mo.
There is no reading/pre-reading or anything like that in the WPPSI, not even in the older kids version, WISC.
