You might want to look up the earlier Jackson bio, Private Demons by Judy Oppenheimer. She didn't have access to the archives that Franklin did, but she did a lot of contemp interviews (Franklin often leans on them without acknowledging it, except in the notes), and it's kind of purple prose, but it does go beyond Jackson's death and is more illuminating about her background overall. I thought Franklin's bio was oddly hostile to Jackson in places and she didn't seem that simpatico, so to speak, it was like reading Julie Phillips on Tiptree. I could see both writers lining up all the facts and doing their best but there was like a fundamental mismatch. Oppenheimer isn't a match for Jackson (no one is) but at least I didn't get the feeling she was not-so-subtly criticizing Jackson constantly.

Oppenheimer's book also has less about Stanley in it, which really annoyed me about Franklin's book. I don't need a giant pages-long detailing of his "legendary" course (which sounds Gravesian and awful)! Unless it had an impact on Jackson in some way! But Franklin never went into the details of whether it did or not, she just really liked writing about Stanley apparently.