Apparently, no, it's not her. It's one of her sisters (they're triplets), Monica. http://www.tv.com/monica-creel/person/40379/summary.html
no
Human by human league
She was in the Christmas commercial, yes.
No. It is not Jaleel White in the new Snapple commercial. The person in the commercial is approximately 50 years of age. Jaleel was born in 1976.
The girl in the new Fiat commercial with short hair is Catrinel Menghia.