Plus size clothes for children?

[cakeandduvetday]

My two nieces, aged 5 and 8, are coming to live with me and will need new clothes.

They are quite overweight but not particularly tall for their age.
Does anywhere do plus size casual clothes for children or will I just need to go up a couple of sizes and get stuff taken up?

My daughter was very overweight as a young child, but lost all the puppy fat as she grew up.
IIRC Next do a plus size range, which used to be good. Other than that, things like leggings, tshirts, sweatshirts are easy to size up without looking too long.

Good luck on taking in your nieces, it's very admirable of you.