I got these

Image The last time I went to BigW they weren’t as good as I remember. Not sure what size you’d need but my 11yo Miniest takes XS, Elder 13yo takes S, my fat ass takes M, and Mr P takes 2XL. They had up to 4XL that I saw. Mr Ps Mum also wears them because they are roomy enough in the caboose to fit her incontinence pants.