The kid will be easy walking distance to Morrisons and Aldi’s and is going to begin her new self-catered life. What’s a reasonable budget for a kid who likes to cook?
I’d say most groceries are 30-40% less expensive in the UK than in CA, but fresh meat is still quite costly. Is she cooking for just herself or for a group of room-mates? If just for herself then I’d guess 50-70 pounds per week (including packed lunch) is doable depending on whether she eats much meat. Shared cooking might be a bit cheaper.