I'd recommend she go with the base M1 MBA. Superb, lowest cost, and will get her through the next two or three years of high school. Her laptop needs will likely be quite different come sophomore or junior in college, especially when she picks a major — 4 to 5 years from now!
The savings could go to Apple Care, external SSD or HD, needed software, and so on (although check with her school first as they may well have a license for different programs).
She can, then, buy an amazingly new Mac if needed that fits the computing needs for her major. Her M1 could become her backup, even perhaps the one she schleps to class and the library…
Or, even thinking differently about this. What about an iPad 9 for now? Perhaps with a keyboard. It's an even cheaper solution and should get her through high school, unless there are special programs she needs.
Of greatest importance:
What does she think about all this? Getting her involved in the decision-making and trade-offs would be good financial and life experience — and, after all, she's working and buying it herself!