You are right to be proactive, as research does indicate that individuals with celiac disease can have a higher predisposition to enamel defects, cavities, and periodontal issues, even with excellent oral hygiene. While many people with celiac successfully undergo orthodontic treatment without complication, your caution is valid. It may be beneficial to seek a consultation with an orthodontist who is familiar with managing patients with autoimmune conditions or who is willing to collaborate with your daughter's gastroenterologist or a periodontist. They can perform a thorough assessment of her current oral health, discuss your specific concerns about recession and decay, and create a tailored hygiene plan. This second opinion could provide a clearer risk-benefit analysis, helping you decide if addressing the cosmetic concern of the lower teeth is worth the potential risks for your daughter, especially if they are not currently affecting function or her confidence. 

This is an older article, but still helpful:  

It's strange because I'm pretty sure not too long ago I picked up a loaf of bread with B vitamins, but I can't find a single one now.  Probably cutbacks, everyone's trying to save money now!

Eating grains typically depletes certain B vitamins, so I'm not sure why they decided to fortify with calcium and iron, but hopefully we'll see more B vitamin fortification in gluten-free products going forward.

@HAUS, I was at an event in the UK a few years back. I remember ringing the restaurant ahead to inquire about the gluten free options. All I wanted was a few gluten free sandwiches, which they provided and they were delicious. The gluten-free bread they used was Warbutons white bread and I remember mentioning it on this site before. No harm in trying it once. It's fortified with Calcium and Iron. https://www.warburtonsglutenfree.com/warbs_products/white-loaf/ The only other gluten-free bread that I've come across that is fortified is Schar with Iodized salt, nothing else.