Bednobs, yes it is pricey, but in my case it worked. The other thing I would very seriously suggest is that you seek out a local church choir with a good musical reputation and enrol her there. Very many churches can act as a pathway to priory or cathedral choirs and the musical education is excellent - and free. If they can't do that then at least she will start to learn the importance of reading music, timing, soundness on note, singing to hold a line etc..
She is only 9, she could end up as an alto (like me) and believe me when I say that it is hard work to learn and sing an alto line against sops, tenors and basses. Currently, I'm trying to unlearn 'Greensleeves' and learn an accompaniment so I can hold an alto line in a concert next week (we are a small group of singers and I'm the only alto!
It ain't easy - but your daughter will love rising to the challenge if she understands that it is the singers job to interpret squiggly dots on a page and make a wonderful sound.
I don't get the 'only Mum' bit. You are her guide in the world, she will go the easy, failure-headed way if you let her.