Sorry if this is late and has already been answered, but I have been skimming through the discussions about timelines and character ages.
Regarding the timeline and the age of characters, there aren’t any issues or inconsistencies that I can see. The official Star Wars timeline always refers to events happening in years before or after the Battle of Yavin (the battle at the end of the first Star Wars film; Episode IV - A New Hope). They show this by BBY (Before the Battle of Yavin) or ABY (After the Battle of Yavin).
The films are shown to take sit into the timeline as follows;
Episode I – The Phantom Menace = 32 BBY
-10 years-
Episode II – Attach of the Clones = 22 BBY
-3 years-
Episode III – Revenge of the Sith = 19 BBY
-19 years-
Episode IV – A New Hope = 0 BBY/ABY (The point from which all time is measured)
-3 years
Episode V – The Empire Strikes Back = 3 ABY
-1 year-
Episode VI – Return of the Jedi = 4 ABY
-30 years-
Episode VII – The Force Awakens = 34 ABY
Rogue One largely takes place takes place a few weeks or perhaps even just a few days before A New Hope, so we can safely put that at 0 BBY/ABY alongside A New Hope.
Jyn tells the Rebel Alliance leaders that she hasn’t seen her father in about 15 years. That means that the scenes of her as a child watching her mother get shot by the Death Troopers and her father get taken by Krennic take place at 15 BBY; 15 years before A New Hope and 4 years after Revenge of the Sith. So, the plot hole that someone raised about the Empire starting to build the Death Star before Revenge of the Sith is incorrect. They started building it at some point in the 4 years between Revenge of the Sith (19 BBY) and the young Jyn scenes in Rogue One (15 BBY).
Given this timeline, and other material, we know that the various character ages are;
Anakin Skywalker / Darth Vader
Born 41 BBY
The Phantom Menace – 9 years old
Attack of the Clones – 19 years old
Revenge of the Sith – 22 years old
Rogue One / A New Hope – 41 years old
The Empire Strikes Back – 44 years old
Return of the Jedi – 45 years old
Obi-Wan Kenobi
Born 57 BBY
TPM – 25 years old
AOTC – 35 years old
ROTS – 38 years old
RO/ANH – 57 years old
Luke Skywalker and Leia Organa
Born 19 BBY (at the end of ROTS)
RO/ANH – 19 years old
TESB – 22 years old
ROTJ – 23 years old
TFA – 53 years old
