Hello, thank you for the question.
I'm afraid that you don't have a lot of options. You need to bring this to court on an emergency basis if you're going to do that route, and that's not a guaranteed result without the input of the child welfare authorities. So first thing tomorrow, contact the MCFD branch which was involved earlier and tell them what's happening. Then you can at least put in your court papers that you have done so.
If you get an emergency order, which could be issued the same day you file, you can then enrol the child in school on the same day. However, if you go to court nearest to you there's a problem. Your court could assume jurisdiction over the child, but the preferred jursdiction is the one where the child lives primarily, ie at mother's home. This is part of the reason why I'm saying that an emergency motion isn't a slam dunk.
You ask about your child's rights. The child is a minor and doesn't have the right to say where she will live or what the access regime will be. If the litigation gets off the ground, I'm pretty sure that the court would appoint a lawyer or social worker to help bring the child's views and preferences to court, as a piece of evidence. But the child does not have the right to decide. As the child gets older and more mature, and understands what's in their own best interests, the court is more likely to give the child what they say that they want. But they never have the absolute right to determine those issues; if the parents can't decide then the court does, not the child.
Does that make sense? I'll await your questions or comments.