Buying for someone picky and not sure if you should risk it? Get them a LoWo gift card instead so they can choose their new favourite glove.
Bottom of Palm to top of Middle Finger (in.)
Approximate: Extra Small 7.00-7.25 Small 7.25-7.50 Medium 7.40-7.70 Medium/Large 7.70-7.95 Large 7.90-8.15 Extra Large 8.20-8.50
While our gloves are in men's sizing, many women still like to wear the smaller sized gloves. General rule of thumb for finding your size is to go two sizes down from your normal women's glove size (Women's L=Men's M, Women's M=Men's XS)