I'm pretty confident in saying it would use at least one year of a basketball scholarship. If she left the team after the year, I'd think it would stop counting, but it is possible it'd count the rest of her time at ND. Wouldn't make sense to me, but we're talking about the NCAA.
That being said, I don't know how many VB players are on scholarship. If it was a non-scholarship player, I don't think it's use a basketball scholarship. The problem might be that all volleyball players receive a partial scholarship. I think that'd then go in the basketball bucket.
Long story short, I don't expect it to happen for a Sweet Sixteen game.