*I've been veggie over 30 years now.
It's much easier now than it used to be. I really like quorn, Linda McCartney and cauldron foods products. Some can't tolerate quorn though so proceed with caution. Some vegetarians don't like the meat like textures, this is personal choice. Talk to dd and see what kind of thing she fancies trying. Quorn and cauldron also do "deli slices" which are veggie versions of sandwich meats.
My dd is a meat eater but will happily eat certain veggie dishes with me. As pp have said you don't necessarily have to be cooking 2 meals as such. You can cook the meat separately to add later.
Honestly eating meat 6/7 times a week is a lot. Aside from the animal welfare issues there's the environmental impact and the health impact of doing so, plus it's bloody expensive!
Taking the examples you've cited:
Paella - meat could be cooked separately even with flavourings if you wish. The rice & veg can be cooked for all at once providing you use veg stock.
chicken curry - this you would probably need to do separately but of course rice and veg can be made for all at once in one pot, again using veg stock. But not massively difficult to have a meat pot and a veggie pot on the go. Veggie meat subs don't need cooking for as long and are really easy to use. Is it a home made sauce? Alternatively you could all eat veggie when you have this either using a chicken sub or having a vegetable curry.
spaghetti bolognese - pasta can be made for all in one pot. Meat mince in a pot, veggie mince in a pot. Again I can answer better if I know what sauce you use. Or again you could go completely veggie for this meal and have pasta & veg with sauce
fish - dead easy to cook the fish separately and make the accompaniments veggie friendly so you make them as you always have. Veggie dd could have a veggie grill/burger/fillet instead or even quorn fishless fingers which are quite nice, or any number of breaded or pastry veggie options.
risotto - again you could add meat after
prawn linguine - again could add prawns at end. Dd could have preferred veggies instead (baby corn, mushrooms, peppers etc)
pizza or something at the weekend. - most takeaway places have veggie options now, if frozen easy enough to pick up a veggie pizza for dd or even let her make her own with ready made base, sauce, cheese & veg.
You do need to be careful to make sure she's getting enough iron, vit c (to help absorb the iron), b vitamins, protein and fats as she is still growing. Check out the vegetarian societies site to start with.*
Thank you for your reply and advice. The Paella is all seafood which I add at the end anyway so that should be enough! Prawns go in at the end for every linguine or spaghetti dish I make too so that's always easy. I make everything we eat from scratch so the bolognese would prob have to be two separate pots but I usually do a big batch and freeze so I could hopefully do that with whatever i substitute the meat with? Pizza is always margarita anyway so no issues there either 
Got lots of great websites etc to check so I'll start a list of new recipes today - again, thank you all for your help!