Clodagh Cogley suffered injuries to her spine and legs in the balcony collapse that took the lives of six Irish students in the early hours of Tuesday morning.
Clodagh's brother appealed to the author on Twitter to send a message to his injured sister, who is said to be a massive fan of Harry Potter and is listening to audio books of the series during her recovery in hospital in the US. Rowling, to her credit, responded to his appeal last night wishing Clodagh a "very speedy recovery".
Wishing Clodagh Cogley a very speedy recovery and sending much love to her, her friends and family xxx— J.K. Rowling (@jk_rowling) June 19, 2015
The tweet has had the desired effect as Clodagh's face apparently "lit up" when she was told of Rowling's tweet.
Clodagh, 21, is granddaughter of former RTÉ rugby commentator Fred Cogley.
We all hope Clodagh gets well as soon as possible.