I have ordered maternity clothes online and noticed that some of them do seem to have some of their range of plus size. Try searching for plus size maternity wear on the internet - a whole heap of hits came up when I did it just then with sizes up to 26 & 28.

Internet ordering is really good - there is soooo much more range than what you can buy in department stores at the moment (most of which is pretty dismal) and there are no other places to buy maternity clothes in Townsville so I had to. Most of them will let you return what you order if it doesn't fit and let you try a different size or go for a refund. You can also find lots of really good specials on the internet of end of range stuff in one or two sizes. I got a black satin maternity skirt in size 16 reduced from $90 to $15 in one of my orders. I love a bargain!

I hope your sister can find some maternity clothes - half the fun of being pregnant is dressing your bump