Go to Holland & Barratt or one of those Afro Caribbean hair shops, you can get a large tub of aloe vera gel, keep it in the fridge and keep applying liberally. Also, get a big *** tub of aqueous (sp?) cream and for the next few weeks, when you shower, use the cream and NOTHING ELSE to clean the sunburned parts.
You live in or near Glasgow? Get your mum to go to the sk:n clinic on Gordon Street (I know they're open Sundays) and get a tube of this: https://www.sknclinics.co.uk/shop/pr...pair-cream-1oz
The CU3 cream is THE ****, I've used it after having a chemical peel, the copper peptide formulation is what helps skin recovery after trauma such as burns. It has the consistency of Vaseline, a little goes a long way, and I still have half a tube of it 3 years after buying it.
EDIT: Yes tigz, great minds think alike! Speaking of aloe, if you regularly shave i.e, face, legs, arms, bikini line -anywhere really- keep the aloe vera in the fridge and use it instead of shaving foam, it TOTALLY eliminates any possibility of skin irritation