Remember that till they hit a score of 5 in it, if you refuse to speak to them in anything BUT latin, it counts as quality 8 instead of 3.
Additional option - send the (proto) apprentices to the local (probably rural) parish school for 2 seasons out of the year (A&A, pg 79); assuming they don't get beaten up due to The Gift, and a sufficient price is paid for their education, you can get someone to teach them Latin and Artes Liberales - which is what they need to start being a magi - or at least to start reading hermetic books.
(Of course, in PC character creation, this requires that you take the Educated virtue, but if you're doing it in-game for your NPC apprentices, then it's free! Sort of...)
Assuming the priest is competent (Com 2 + Teaching (children) 3 + 3 = 8 XP/ season), you'll only need 4 seasons across 2 years to get them capped out in Artes Liberales (2) and Latin (2) - which is really enough, anyway: they don't seem to be doing anything else during the early years of their apprenticeship, except maybe getting Exposure to Magic Theory, or something. They'll probably pick up more from Latin practice around the covenant, though.
EDIT - or have one of the grogs be their Lupus (A&A, pg. 91), forcing them to speak Latin at all times - which forces them to use their "Free" seasons to do total immersion training. (I would agree with the above comment that children, by themselves, probably wouldn't do this voluntarily. They'd pick it up eventually via Exposure, but not as fast as if someone was standing over them, forcing them to conjugate their sentences.)