Lowering it 1" isn't too severe. If the bike is slammed and hard parts start hitting things before the suspension bottoms out then yes, I agree. I doubt that would be an issue with it only being lowered 1" though.
regardless, it's still arguably less than optimal.
over the years, i've become a firm believer of setting the suspension up properly and not cutting corners.
i've come to this conclusion from almost wiping out from a bad suspension set up (by a well known shop), and feeling how different a proper set up can make the bike handle.
my suggestion to xtina is to have the suspension properly sorted out and not assume anything is optimal just because she may weigh 140lbs -- especially since she's lowered it a full inch (and not knowing who or how she's done that)
ps. xtina: you don't have to be riding all out on a track to have suspension issues muck up your day. trust me, i know this from experience.