I know it is hard for trousers if they are growing tall and sometimes you can let the hem down but the way the clothes are made now they have cut back so really nothing to let down. I would be looking for someone to help sew unless you can and make the uniform.

My daughter was 880gram at birth, we bought online and I made myself as everything in the shops was too big

Clothing sizes are hard enough for kids and adults. Target are pretty good with the adjustable waist pants

Target are pretty good at catering for all shapes, sizes and heights. I find most of what I need here

Target and Best and less are really good for this

Target have the school shorts with the pull string waist that i’ve found are quiet tight pulling.

I don’t know if you’re able to alternate clothing yourself ? Otherwise I would let it alternate by a seamstress.