Don't worry too much about the number on the scale, syrians can be anything from 100-300g with some *cough* Neptune *cough* pushing 350g so it's not so much the number that's important, it's changes in weight. Weigh her every week or so and keep an eye out for sudden losses in weight or changes in condition. If she's not bony when you pick her up, she's active, her ears are up and interested, her eyes are shiny and clear and her coat is smooth with no patches then it's safe to assume she's ok.
Edit: of course if you're worried about her being a bit thin you can feed her nice fatty treats like mealworms, the odd bit of cheese or shelled nuts. They're very active little animals so it's pretty hard to get them really fat