My daughter had her braces through Apple and they've done a great job, however if your 9 yr old has not lost all their teeth then do not have braces put on, because they will need them again later on in life. I've talked to a lot of parents that their children had braces on before they'd lost all their baby teeth and they ended up getting braces again around age 16. Either way after she has her braces she'll have to wear a retainer basically the rest of her life.
I had dental insurance that covered orthodontics so it only cost me about $2500, but the total was around $5k. The good thing is they let you pay it out monthly with no interest.