Congrats on your new pony & your big adventure!
I think you've gotten really good advice. Another thought is to aske the YO if there's a student or want-to-be student who could work your pony during the week. Maybe there is someone who doesn't have their own horse who would jump at the chance to have access to one. I would definitely get the YO's advice on this, as you don't want someone treating or using the pony contrary to how you want. Or if your pony is trained enough, perhaps it could be used as a lesson horse during the week? Just keep in mind that in lessons, it might be treated more timidly or more roughly than you would.
I would also recommend getting a lesson, at least here and there, for both you and for your daughter.
Read lots of books, watch videos, watch others in lessons, ask questions, visit this forum. Knowledge is power, but you definitely need to just get on and ride! Ride in a sand pen (don't know what that is, I'm guessing what we would call a round pen or maybe arena??), or somewhere you can feel safe. Just like Barry said, walk, trot, stop, back up. Work with her on the ground, groom her, but make sure you RIDE! Riding is the surest way to overcome your fears of riding!
John Lyons is a clinician and his first rule of working with horses is that you can't get hurt, and the horse can't get hurt. So don't do things that are beyond your ability, but do stretch yourself. And if you need help, ask for it.
Keep us updated on your progress, your daughter's progress, and your pony's progress!