What is a normal monthly amount to give a seminary girl for spending money (excluding public transportation - which is on my Rav Kav and CC)?
It varies widely, depending on the standard of living you want to support, if you want the student to pay for some of their more discretionary spending, if the student has their own funds to supplement that as needed, as well as the current exchange rate and inflation. . .
but $150 US /month, should often be enough for basics+, (without leaving the student deprived) assuming meals are generally available in the seminary and student is in a dorm (no rent or utilities expenses).
Covers things like additional food, trips, gift to shabbos hosts, laundry, cleaners, cell plan, etc. (Transportation can be substantial, depending on location, so maybe less without that).