Hello there
@Shabs , and welcome!
Love making children's clothes especially frocks. If you could take a picture of the problem area, and the pattern you are doing, we will be able to help rather more.
I'm making a dress/costume atm, and I've made a practise garment (toile), because I know my GD has grown since I last sewed for her. A toile is just a simple garment - no facings, no fancy finishing, just enough that you can make adjustments and transfer the adjustments to your frock. Use an old sheet, or duvet, you'll be surprised how much fabric there is in them.
Jessie