I help women in La Leche League all the time, who have problems with oral thrush in their babies, as well as on the mom's nipples. We tell them to use gentian violet all the time. It usually takes three days to clear up with that. Since, I'm assuming, that you're not breastfed anymore, your mom won't need to put the stuff on herself.
Yes you can pass it on to a woman during certain activities... and remember as I said above, you can pass it on to her nipples as well. So, be careful with that.
