Should I change pot?

Hi all

My mum's curly grass really isn't looking healthy and has lost all by one half-yellow shoot. It is currently infested by soil mites and is cramped inside a small pot - way too small for its (original) size. Would it be a good idea to move it to a bigger pot now and fix the soil mite issue? Or should it be left in the current pot and just sort out the soil mite issue?

Thanks