There seems to be a lot of people acting in bad faith when it comes to Mercy’s age, saying the writers are retconning stuff. So if you see any of these people around the internet here a topic you can direct them to point out how they are wrong and they are liars.
More importantly I hope this make the life of people that like to archive stuff, make timelines and inform people here on the story discussion, easier.
Here is a link to the old OW1 site Mercy profile (at the day of the game’s release), showing her age as 37:
In the Recall animated short at the 7:17 mark you can see Mercy’s profile with the age of 37:
This is a talk where the ex-lead writer explains that in the old picture in Ana’s origin story Cassidy was just recruited to Blackwatch, Pharah is 11 to 12 years old and Mercy as an university student visiting Overwatch, so not an agent. Meaning that she must be about 17 years old in the picture (50:54):
A screenshot from the old OW1 forums where the lead writer mentions that Mercy was not an Overwatch agent at 17 years old and that both she and Tracer age:
Another screenshot of a post made by the lead writer in the old forums that clarify the 2 images that shows the members of Overwatch, the age of the original strike team is incorrect, and that they should’ve looked older:
OW2 takes place 2 years after Recall so Mercy’s OW2 profile site shows her updated age, 39 years old (37+2):