She’s made a series of transphobic comments.
See all the other comments on this thread and read what she actually wrote to see if you believe this is true. I don't.
There are other things too (using the name of a pioneer of gay conversion therapy as her pen name,
This has been completely debunked. It's not true.
racial insensitivity in some parts of the Harry Potter series
Really? What parts? Can you give examples.
vocal support for Johnny Depp after it emerged that he had assaulted his wife,
Yup, I'll give you this one, it was disappointing. Doesn't make her a terrible person, most people were doing that at the time and there wasn't a huge amount of evidence against him at the time. Still disappointing in my view.
retconning diversity into Harry Potter for credit
Well ... it would have been better if she'd been more explicit about Dumbledore being gay in the series, but a lot of books of the period, and even now, are not that diverse.
but the most prominent criticism is the transphobia.
Yes, so see if you think there's anything in that.
Against that are the millions of pounds and constant effort over decades that she's put into important causes, including support for abused women and disadvantaged communities.
But yeah, the fact that she thinks women should have access to single-sex spaces means you should hate her and never talk about her.