I agree with what everyone's been saying that it isn't the numbers necessarily, but the (intense) quality of the hours spent together that caused Jen to think that this was more meaningful than it was.

"I honestly feel like a week and a half and 3 dates is way too early for that conversation anyway."

The way the OP phrased this, it's easy to say that he's completely right to be blindsided by the intensity of Jen's feelings. He might even say she's one of those "crazy" chicks. However, the '3 dates in 10 days' really mischaracterizes what happened by reducing it to just those numbers.

This isn't 3 dates meaning: (1) coffee for 1 hour one day; (2) dinner for 2-3 hours another day; and (3) dinner and hookup but no sleepover - with only occasional texts in between with content mostly aimed at setting up the dates.

The OP and Jen had MULTIPLE skype sessions before the first date (how much time was that total?), things "got physical" on the first date and included a sleepover. The other two "dates" were also sleepovers.

So if you add up the time they spent together (36+ hours? plus the skype dates?), it could easily translate to 4+ weeks of "casual" but escalating-in-intensity dating.