We are a vegetarian family (both parents and kids) - we do include some dairy (cheese, yogurt), mainly for the reason that my kids are very picky eaters. So I don't have the experience of suddenly having to cook different food for a child, but I will list some resources I found helpful when my kids were younger (and we had relatives questioning feeding choices).
The good news, is that there are so many more meat-free options available now than there were when I became veg (after university). So you can probably find relatively close meat-free analogs to your child's favorite foods. Vegetarian burgers, veg. hot dogs, sliced 'meats', and so on - they get better all the time. And if your DD is not fussy - great! You have even more options! You might try going slowly and replacing meat one meal at a time, see what works, or doesn't...

I found this book helpful: Raising Vegetarian Children by Joanne Stepaniak
And if you pack lunches, some good ideas in here:
https://www.goodreads.com/book/show/2220485.Vegan_Lunch_Box

Some links:
https://www.vegetariantimes.com/health-and-nutrition/raising-veg-kids
https://www.eatrightontario.ca/en/A...o-Know-to-Raise-a-Healthy-Vegetaria.aspx

HTH!