I think that there is a junior range of nappies out, but not 100% sure who makes them. I know my gf had to use them on her son as he was and still is a chubba.

We have the opposite problem with Tehya. WHile I don't mind the Aldi nappies, they come up so high and the tabs nearly cross over on her. She is 15 months and only 9.3kgs. Huggies fit her great but I only buy them now when I can get the box for $30 on sale.

What about going cloth?? Just a thought. ummm ok just to mind I think there is a brand that the chemist sells that have junior sizes in, from memory they aren't too expensive either. Maybe have a look there