I can't vividly remember going to one of these when I was little grades 1-2, other than I do have a vague memory of one. An All Soul's day Mass, perhaps? I'm sure there must have been the odd school Mass or two when we were present at someone's funeral if the Mass time coincided with the school Mass time (as it sometimes did.)
I think if a person has ever been to a funeral service for someone they didn't know, you can almost count on that person being Catholic. I can remember in the mid 60s, after the Mass went to mostly English, but with the old form largely retained, before the 69 missal, we went to quite a few funeral Masses. From middle of 3rd grade through 7th, I'd attended two different schools, and we'd normally all go at least once or twice a week to Mass as a matter of routine. Both churches were cavernous -- so the family of the deceased was usually no where near where we sat, even with the whole school going.....which was just as well, given the propensity for the younger kids to stiffle not tears over the casket scene before us, but generally over "Drama queen" soloists. I can well remember a classmate or two being taken to task for getting the giggles. No, it was never me. I'd already been too scared to even so much as turn around during Mass, because our primary school nuns grades 1-3 would have killed us. That sort of nun can help you develop Vicky Lawrence type immunity from breaking out a laugh. Or as George Carlin would say "if you were good, you could whip a face on Rodger, and HE'D get in trouble for laugning, but NOT you. 'Rodger, outside, there's nothing funny here.' IF you were GOOD, you could clear the whole room."
Many of my protestant friends, when Iwas growing up thought it must have been gloomy for us to have to attend these masses. Far from it!! These usually took longer, so we enjoyed the extra time out of the classroom!
[In grade school, 4-5 in Roanoke, Virginia, I had a friend, Teri Jo Myers, who was a genius at getting a nosebleed, which conveniently lasted from the gospel reading to just before the consecration. Guess who would get to go with her to make sure she was okay and didn't pass out? A few years back one of our servers was telling us that in grammar school they LOVED to serve Mass for Fr. Tom P. because "he always told us we didn't have to be in any rush to hurry back to class." I daresay as a boy in Ireland he had a clandestine few extra minutes of bliss away from the nuns with the priest's permission.
What goes around, comes around!