how old was she in goosebumps?

It's not that hard to figure out. You go to her page and see what year(s) she did Goosebumps. Her page says 1997-1998. Then, you take those years and subtract it with the year she was born to figure out how old she was.

I met her recently at a small convention in LA and brought up Goosebumps and she mentioned she was 14 years old when she was on that show.