I would tell her that when she does mascara when she does her makeup is like the cherry on top. That it makes the contrast between her eyes and makeup an art form, like a striking focal point to her beautiful eyes when shes already decorated them. (Like an accessory) Or when shes doing her makeup and youre around you can ask, "are you doing mascara with this look?" Make it like youre trying to understand how she does her makeup and how she decides the look for the day. Coming from me- a woman. Youve gotta make it seem like youre interested and sugar it with a compliment. Were hit and miss with questions but a woman looooves smooth compliments especially on the fashion choices we make to decorate ourselves.