There is a lot to consider here, most of which has to do with the kid. Here are some questions that I would consider.
*Is she emotionally mature enough to be on her own or would she benefit from another six months in high school?
*Is softball her life or does she have other interests/friends/activities? Will she regret missing things like graduation, prom, etc.?
*Is she going to redshirt and the idea is to get her in the program and start lifting/training? Or are they planning to play her?
*Are there financial incentives to go early? I have no idea what sort of NIL a top P4 softball recruit might get, but that is a consideration.
*How strong is she academically? What are the academic implications of going early?

At the end of the day, it is a highly personalized decision.