You know what? Obviously, they're not the same person. Maybe Riley is that woman's daughter. They look awfully similar, and of course, the age difference is very obvious.
I can't find a link if anyone knows it please post. In a video Neil Druckmann states that Riley is exclusive to the comics.
Yeah Riley is exclusive to the comic. He revealed that on a twitter question and answer event. The comic spans one night. I also asked him will he consider making a comic seris based on Joel's backstory, he said Joel does have some interesting history, we'll see (judging how quickly issue #1 is already on it's 2nd printing, it's very posible)