Former ABC broadcaster Margaret Throsby, 84, is recovering in hospital after being struck by an electric "fat bike" while walking on a shared path in the Illawarra, south of Sydney, last week. Because nothing says "shared path" quite like a motorised couch with two teenagers on it.

Her daughter, musician and author Holly Throsby, said the 84-year-old required surgery after a high-impact collision with two teenagers on a fat bike left her with an injured hip, thumb and head. The boys, she explained, "seemed to impact her on one side, and she went down on her other side and broke her hip."

"It was really quite a sickening scene to witness, just because there was so much blood," Holly told Guardian Australia. "Her whole face was really covered in blood, and she had two massive haematomas on her head which was super alarming." For those keeping score: one grandmother, one hip, one thumb, one head, two haematomas, zero helmets mentioned.

These speedy ebikes - with wide, thick tyres and seats big enough for two - are commonly seen in coastal regions such as the Illawarra, presumably because the laws of physics needed a vacation destination.

Holly, who was contacted by bystanders who came to Margaret's aid, said police attended the scene at Sandon Drive, Bulli, and have kept in touch about the condition of her mother. "When the paramedics arrived and tried to move her, she was in so much pain from the broken hip," Holly said. "So they gave her some pain relief and got her on a gurney and got her into the ambulance, and she had surgery the next day on her hip."

She says the teenagers looked "completely mortified and scared" and she wouldn't want them charged - a level of grace that suggests Holly Throsby may be a better person than most of us.

A NSW police spokesperson said officers spoke with the rider, a 16-year-old boy, and his passenger, who remained on scene and assisted the woman. "Inquiries are ongoing into the incident," police said. The next day, police conducted Operation Spoiler, targeting the use of illegal ebikes and trail bikes within the Wollongong and Lake Illawarra districts. The high-visibility operation ran from 8.30am to 6pm and saw traffic and highway patrol officers, assisted by local general duties police, and specialist trail bike police, bicycle police, and Polair. During the operation, officers conducted 37 ebike stops and issued four infringement notices and two cautions in addition to 15 youth warnings. An officer said the operation was unrelated to Throsby's accident - because timing is a hell of a coincidence.

Holly called for legislation to govern the use of ebikes by kids. "I think the more appropriate measure would be to look at ebike legislation, education and training and some kind of licensing system," she said. "For kids to be riding those bikes [which are] massive and heavy … it does seem inevitable that this kind of thing will happen." In related news, water is wet and gravity remains undefeated.

Margaret Throsby AO joined the ABC in 1967 and was the first woman to read national radio news in 1975 and, in 1978, the first woman to present national television news. She hosted a high-rating morning program, The Margaret Throsby Show, on ABC Radio Sydney and in more recent years hosted various programs on ABC Classic FM and Radio National. A trailblazer for women in broadcasting, now recovering from a trail bike of a different sort.

Holly said her mother was in excellent health and she expected her to recover well, although it may take some time with rehabilitation needed for her hip. So the next time you see a fat bike barreling down a shared path, remember: it's all fun and games until someone's grandmother needs a hip replacement.