I had 7 teeth pulled in preparation for braces. I also had a palate expander before I got braces. It was cemented to my teeth and basically made the roof of my mouth flat across. It was very very hard to eat and speak. I had to expand it daily for 6 weeks then wear it for another 6 months. During the expansion phase I had to get up for school an hour early every day because expanding it was so horribly excruciating. I cried and trembled as I did it each morning, then had to have time to pull myself together and let the teary redness leave my eyes before getting on the bus.
It was far from fun, most definitely not a fond memory or good experience, but this is the age everyone is getting orthodontic work done. She should wear all dental appliances exactly as directed, and maintain all her usual activities as much as possible. Dropping out of life is not a positive way to cope with a challenge. She'll adjust much much quicker, and get better longer lasting results, if she just has to suck it up and be tough from day 1.
It is impossible for her to understand this perspective now, but as an adult she will be glad you spent the $ to fix her teeth at the appropriate time of her life.