I was wondering if Livia was as manipulative and forceful a character as the book portrays her. She seems to control Augustus quite strongly.
I found this website, Ancient History Encyclopedia, which looks to have some interesting articles on Roman history.
https://www.ancient.eu
It has biographical articles on the various people. Here is a link to Livia's page. I haven't read through it yet because I don't want to spoil what's coming up in the book.
https://www.ancient.eu/Livia_Drusilla/