My grandmother lived in a DoD dorm as you describe - grandpa used to walk about twelve miles each way to see her.
Note that I exist.
The dorm rules meant nothing.
I know your grannie must be proud that you outed her as a woman who got pregnant before marriage. Was that your intention?
Back in the day, not so long ago, she would have married your grandfather, had a big big baby for a seven monther and we all would have said “oh what a large premie”.
But you come along and throw grannie under the bus for your argument. Shame on you.
I seriously doubt if your grandmother was doing a bunch of boys starting at age 12 or 14. Or that your grandfather was a porn afficiando or had experimented with homosexuality, or had tried dozens of women.
All of which are unfortunately not uncommon now.