Was also going to suggest a baked cheesecake with a GF base
Yes this. For the base use almond meal, sugar and butter. Or crushed gluten free plain biscuits, mixed with butter.
What about some Indian style desserts, such a khir or burfi?
Lemon sago pudding.
Baked fruits (eg stuffed apples), with packet custard (made with the gluten free custard powder - White Wings??)
Creme Caramel (the eggs are cooked).
If you make pavlova it will surely have to have fruit on it? What fruit would you put on, seeing as she won't eat fruit salad? She might not eat pavlova either, as I guess the topping is just the same as fruit salad?