She shared an article on grief and made the comments on Saturday.
Fans of the Harry Potter films have been left devastated by the death of 69-year old actor Alan Rickman, who played Professor Snape, last week.
She Tweeted to a user called Sean-Patrick Burke: “’I’m so sorry to hear about your aunt. Yes, collective grief can be cathartic, a chance to release private grief. “
Mr Burke had written: “My aunt died the week before Bowie. It’s easier to publicly say I’m bummed by him & Rickman than the loss of someone close.”
Earlier, Rowling had shared an article about loss. She called it: “A beautiful piece about mourning heroes and our cultural phobia of open grief.”
Rowling then continued on the same theme, telling followers: “Perhaps the old mourning rituals weren’t all bad.
“We wore black to explain why we weren’t up to faking cheeriness.”
Colleen Ann wrote: “Thank you so much. People’s kindness is the best medicine for such things.”
Melissa Westbrook wrote: “People don’t like to talk about death and may need reminding that it happens to friends and family.Looking the other way doesn’t help.”
Renowned British film and theatre actor Alan Rickman died in London on Thursday aged 69.
He was said to be Rowling’s first choice to play Severus Snape in the Harry Potter franchise, and was one of only a few people she trusted with his character’s secrets.
He also played villains The Sheriff of Nottingham in Robin Hood: Prince of Thieves and Hans Gruber in Die Hard.
Musician David Bowie also died of cancer on January 10th.
On Thursday, Rowling had Tweeted: “There are no words to express how shocked and devastated I am to hear of Alan Rickman’s death. He was a magnificent actor & a wonderful man.”