My son was diagnosed with type 1then three months later coeliac, two months after that my daughter was diagnosed with coeliac and two months after that so was I!!
I won't pretend it was easy in the beginning, however with the amount of choice out there in supermarkets, online and via prescription it's not too bad, initially you will experiment with new tastes and build up a repertoire of foods she likes, eg we prefer warbutons bread to genius, etc. , but you will find that you will spend more time in the kitchen together, eat more freshly prepared food and even eat foods that your daughter may have not liked before as the GF alternatives are much nicer (pizza in our case).
The biggest problems I have found are price and their peers. It's an expensive diet, so you will need to shop around and do some research, and others who don't have coeliac disease do nor always understand the gravity of the slightest bit of contamination, ( my children become very ill indeed). So it's a learning curve for everyone.
Our small rural village primary school has been amazing and their friends are very thoughtful, you will just need to be vigilant when she goes out to restaurents etc, phone ahead to check their GF availability, plus you will become a great packed lunch maker.
Another tip is get rid of all wooden utensils from the kitchen and buy a toaster for her, so she can always have toast safely.
A warning, be careful if she ever needs to spend time in hospital!! I am battling with this at the moment. If she needs to spend any length of time in hospital take all her food in with you and don't rely on the NHS to be able to supply you with anything suitable for a type 1 coeliac. We learnt that the hard way.
We'll end of lecture! ,
I hope this has been of some help to you and I hope your daughter begins to feel better on her GF diet.
Lucy x