That would be a question for the AD and their rules. Personally, I have never heard of it around here for HS sports. I don't know how, locally, they would get in their required practices for each sport to be eligible to play in games.
It would seem to me that the team cohesiveness would affected when she doesn't show up for practice but can make the games. Having experiences with both sports, there is so much more in softball that needs to be worked on than soccer, I can't see how missing softball practice would be acceptable.
Wouldn't that depend on the team, size of school, class, number of willing participants, etc.?