Translation:The children are getting educated at the school.
Respectfully suggest: being educated should also be acceptable, and is actually the correct translation. "Getting" is not actually grammatically correct, just very commonly used (I use it myself a lot).
This is still not accepted in October 2018. Is the course still being maintained?
would it be correct to also translate this as "the children are educated in the school?"
I think so. Technically school here is definite (בית הספר), but it can be understood as a generality.
Not knowing the context, how can one guess if "מילדים" is "the children" or "the boys. I believe both shall be accepted