I’m going to take a different approach here. You bought a likely pretty expensive trainer rather than upgrading her bike. I would have upgraded her bike with the funds and bought a “dumb” trainer rather than a possibly inconsistent trainer. You can get cassettes chains and things pretty cheap on Ebay and other cycling sites. Scour craigslist and the like for parts or trainers.
The Neo is $1k+ correct? Flux $750ish? I’d much rather have a good working bike than a trainer I’d likely only use 3-4 months a year and randomly in warmer weather.
10 spd stuff is pretty cheap. No need to jump to 11, but even still, that is pretty easy to source on ebay using shimano 105 for a decent price. Certainly less than the Flux.