I know her as Megan from the Progressive TV ad or the gal from the latest Milo's Dog Treats TV ad. Melamie is very recognized and memorable by her voice, however she was on Notes from the underbelly and I don't remember her from that! Also found that Melanie has worked with Yoplait and 1-800 Dentist.
So I would say between 8 and 13- depending on the maturity level of your child. In texas there is no law that stipulates when a child is old enough to stay home alone. In fact there was a news story on this just this month (I'm pasting the details for you below.). Good luck!
The National SAFEKIDS Campaign recommends that no child under the age of 12 be left at home alone. However, consider a child's age and maturity level. For example, if a child is extremely impulsive, it might be best to wait until he or she is older than 12. There appear to be very few states with specific regulations about the age of a child left at home alone.