L8 in 7th grade is enough time. What she needs for college gymnastics are the requirements and 10 SV routine on at least some events (or a really standout event). So by 11th grade hopefully she would have at least one D skill on the events she hopes to continue in and then connective bonus and all the requirements. On bars it would be preferable to have a same bar release, not just a transition from low to high bar, but it is not an absolute necessity. Dismounts on bars and beam, need a C dismount (minimum usually a tucked double back off bars and front full twist off beam OR back 1.5 twist). Acro series with a salto on beam (ex: BHS back layout). Vault will generally need a 10.0 (ex: laid out yurchenko 1/2 or full). If she can contribute on other events and they just need a vault substitute, then showing for example a front front vault would show she has potential to contribute on that event, but probably wouldn't be a starter or big scorer in the line up.
Many girls doing college gymnastics did their first year of L10 their sophomore year. A fair amount may have done it their junior year. I even know walk ons who weren't L10s in their senior year, but they usually had some mitigating circumstances. If her goal is just to get on a team as a walkon, if she can avoid injury and keep progressing, five years should be sufficient. A scholarship is much harder to count on because that depends so much on her skills and competitive ability/experience vs how they're looking to fill their line up. When you talk about girls verbally committing early that's generally for scholarship purposes but there are a fair amount of walk on spots. Some are recruited spots where there's an unofficial commitment around the junior year or even the beginning of the senior year I've seen, it really depends on the individual teams and how it works out for them. If you're walking on then you need solid skills with potential to contribute to the line up (i.e. generally at least the base routines) but it won't generally be as competitive as the scholarship pool.