This has series has caused quite a stir in the UK TV production world, with many saying that Netflix and the production company that made the series did not do enough to disguise the people involved.
The "Martha" character outed herself publicly, but had already been "outed" by internet sleuths who found her very easily. While they changed her name, they left a lot of the wording of messages the same, they didn't change her job and nor the city that it happened in. And while the series boldly claimed that it was all "True" that seems not to be the case - particularly with respect to how it finishes.
There are lots of people who have had true-life dramas made by broadcasters like the BBC and ITV have said that those broadcasters would not have allowed the script to be made as is.
While someone should always be able to tell their story, there is legal jeopardy if you leave someone identifiable (and changing the name probably isn't enough) and make claims about their behaviour that you can't back up. Netflix in particular seems to have found itself repeatedly in hot water over this, recently settling a case related to When They See Us, and still facing action over Inventing Anna.
Adam