The writer of the hit children's series took part in a Facebook Live chat for her charity Lumos, chaired by broadcaster Lauren Laverne, to publicise the plight of the eight million children around the world who are living in orphanages.
Rowling, who founded the non-profit organisation 10 years ago, said: "All of the research agrees that there's little you can do worse for a child than put it in an institution."
She cautioned people about donating money to overseas orphanages.
"We want to help children and that's an honourable and admirable thing. However, you may be contributing towards real harm."
"If you take nothing else away tonight, I'd like you to remember this is a solvable problem.
"Eight million children is an unfathomably large number - it's so hard to really take in what that means, eight million - but we can solve it. We absolutely do need funds but we need to change minds. And if we change minds we will change lives."
She was asked by Laverne how she managed to keep up with a hectic publishing schedule.
"I have a very supportive family and I never answer emails.
"I find it makes life a lot easier if you just forget a lot of stuff you're supposed to be doing.
"I tend to prioritise my writing and my children. Children normally come first depending on how they're behaving."
She also revealed she has realised there is no escaping Harry Potter.
"As completely as I can ever step away from Harry Potter, I really stepped away for about six or seven years ... But Harry Potter has a gravitational pull of its own because the fan base is so strong that I don't think I'll ever be entirely separate from Harry Potter."
She also answered a fan question about the best life lesson for a wizard.
"The most important life lesson for a wizard is exactly the same as for a muggle, because ultimately those books were about human nature and examining the fact that even when people were given magic, it didn't solve everything.
