I've extrapolated, from the presence of a crucifix and an Our Lady of Guadalupe candle at Jess's gravestone in 1x02 and from her possibly-Irish-derived surname, that Jess is Irish Catholic. I've extrapolated, from the nurse costume in 1x01, that she's a premed. And there's an awful lot of clutter in that apartment and Stanford is the only time in Sam's life when he had the possibility of having more possessions than could fit in the Impala, so I'm thinking just about all of that clutter is Jess's. I haven't taken time to stare at those screencaps, but there's definitely a National Geographic, plants in the windows, and a fuckton of books.

I had extrapolated, from Sam saying in 1x19 that art history is a good place to meet girls, that that's where Sam met Jess, but we find out in 5x20 that another friend of Sam's introduced them. Which is just about the only hard fact about Jess that we don't learn in those three scenes in the pilot, the others being her full name's Jessica Lee Moore and her birthday's five years to the day after Dean's, which we see on her gravestone in 1x02, and that Sam meant to marry her, which we hear in 1x22.

She's a blank slate and her sole purpose was to be a driving factor of one of the character plots in the pilot and, by dying, to kickstart the mytharc. It's frustrating.