Queens skater here - welcome!
Group lessons are generally terrific for beginners and once a week would be fine if what she wants is to learn to confidently move about and have fun on an ice rink. Her first lessons would cover things like basic gliding and balance, stopping, getting up safely from a fall and so on.
The kids groups at Queens go right up through the 10 levels of Skate UK and "Passport" (it's officially known as Skate UK Star if you want to look it up). So she could get all the way up to a couple of single jumps and basic spins in just group lessons, although progress can slow down once you get up to turns and at some point you have to add in practice time as well as lessons. Loads of kids only ever get that far and it's a lot of fun before you get into more time-consuming and expensive advanced skating (which is also fun, but a very different level of commitment).