Coeliac grandchild

It depends on what she likes`I suppose but it is cheaper to buy gf flour and make biscuits and cakes for an occasional treat (perhaps she could bake with you), I find gf bread to be OK if toasted.
You can buy gf pasta and use cornflour as a thickener for sauces.

Someone posted that Nairns biscuits are lovely (for an occasional treat!).

You will have to get used to reading the ingredient labels on everything as so many foodstuffs contain gluten. Some sausages contain gluten, some don't - Black Farmer don't, but check.

It's just best to cook everything yourself from scratch as you will know what's in it.

There are other threads on gf if you do a search.

Good that she has been diagnosed now, it will save years of undiagnosed symptoms and ill-health!

Its good she has a diagnosis. A lot depends on what she likes to eat I guess as to whether you have to buy certain things. You can get gluten free cereals such as porridge, cornflakes, cocoa pops. If she is a sandwich fan then unless you make your own bread, you may need to get some GF.
Otherwise there are LOADS of recipes and ideas online. Anything with rice or potatoes is good. So lunch could be baked potato with a topping and a bit of salad or rice noodles with stir friend veggies. A roast dinner is fine as long as you omit or make your own GF yorks puds and make sure the gravy doesn't have flour in. But if you just google GF meals for children, you'll get masses of ideas. You can make cakes without flour. Again, loads of recipes online. I do a chocolate cake with ground almonds instead of flour and it's absolutely delicious.

It isn't too bad at all to follow a GF diet. There are loads of things coming through now in the shops and in restaurants everything is marked GF. Easy peasy!

Don't forget to be careful of cross contamination, such as putting GF bread in the toaster that's been used for other bread.
Otherwise read all the labels and keep checking in case ingredients are changed.
It might help to join the Coeliac Society as it provides a lot of info and lists of branded GF foods; otherwise cooking from scratch is fine. Avoid Oxo cubes and use cornflour as a thickener.
I have about three adult GF friends and it's never a problem catering for them.

I downloaded information from the coeliac site for restaurants when I visited Spain, but didn't need it everything was clearly marked. Must be an EU ruling.

And don't 'double dip' the butter!
(Following on from Soupy's post)