Elin Hilderbrand, the novelist, joined the University of South Carolina’s parent Facebook group last year, after her son enrolled. “I had to Google ‘DS’ and ‘DD,’” Ms. Hilderbrand said. “I thought it was a Southern thing.” (For the uninitiated: DS is shorthand for darling son, DD is darling daughter.)

From her home in Nantucket, Mass. — also the setting for several of her beachy romance novels — Ms. Hilderbrand was transfixed by posts about the intense world of sorority rush at the university, where first-year female students arrive a week before the school year begins to advance through elimination rounds in hopes of a bid.

“I’m fascinated by sorority rush. It sounds brutal…. The girls seem to have it much harder?” Ms. Hilderbrand posted.

Responses poured in, and Ms. Hilderbrand couldn’t stop reading. “There were literally hundreds of stories about the way the girls have to get up at 6 in the morning and get their hose on,” she said. “There were mothers on there who were completely heartbroken — ‘My daughter was a legacy and she didn’t get in and her best friend and her roommate got in.’ Every comment was a novel, and it was breaking my heart.”

Parents also rely on college groups to ask about mattress toppers, frown on difficult professors (“My daughter is very good in math, but her professor isn’t teaching at all,” read a recent post in a Clemson mothers group), arrange “care-package parties” and set up parent “sip and sobs” near campus after drop-off.

Some look for help finding their children roommates; others complain about them. There are bucking Buckeyes. “I need a little advice!” read a recent post on the Ohio State University (OSU) Parents group. “My daughter called me at 5:30 a.m. saying she had been sitting in the common room since 3 a.m. because while she was asleep her roommate had came in and woke her up because she was having sex in the room!”