Never mind weight, Do it by eye if she's that bit to heavy thin her down if she's too boney put a bit more muscel on her frame, Every dogs diffrent try both tryy running her with that bit extra weight and see how see goes, Then try running her light and see if theres any diffrence,
My two here have to be run on the light side, Iv seen some Sal x's that looked straved but that was just there running weight and run excellent like it, But it anit always nice to see them too light,
Try both ways and go what ever works best for YOUR dog