The consensus of most Poskim is that Maaser funds cannot be used for one's children's education.The Chofetz Chaim
(Sefer Ahavas Chessed, Ch. 19) writes that it is prohibited because "it is like paying one's own debts from Maaser funds".
The issue is whether tuition is a Halachic obligation; if so, a person has no right to use Maaser, which is HaShem's portion,
for this purpose, just as he may not use Maaser funds to purchase an Esrog. However, Maaser can definitely be used for the
education of other children who may not be able to afford the cost of education. Consequently, if a person is paying full
tuition, and knows that a portion of it is used to subsidize the tuition of others who cannot pay, that portion may be taken
from Maaser funds.
In Halachah (Reference:) there is no obligation to educate girls, or even to educate boys past a certain age. Rav Moshe
Feinstein states (Igros Mosheh, Yoreh Deah Vol. 5, No. 113) that nowadays the obligation to educate one's children
extends much further than it did when Jewish society was more insular. However, Rav Yitzchok Blazer (Shaalos
U'Teshuvos Pri Yitzchok, Vol. 2, No. 27) states that if a person is in financial need, he may deduct tuition for his daughters,
and for his sons that are over six years old.