Character depicted as 18 years old and older. I believe she is canonically 23 years old in the film.

In this week's rendition of "Obscure as balls characters who showed up for 10 seconds and now all of a sudden has a LoRa", we have a beta design of Sam Sparks as she appears in the developmental reel for Cloudy With A Chance of Meatballs, seen here:

youtube.com/watch?v=Fn8J1cQt7IM

v2 is here. Trained onsite but it's kind of a mess. Just turns her into a generic brown hair girl. Yay! Also, 0.75 strength is about the highest it'll go before turning into a mess.