The webcomic is great, but I also just love her random comics, particularly the ones about the Hunger Games:
The rest are here.
Since she just writes great comics in general, I think her agent (and HarperCollins) made a great decision taking her on, as she clearly has plenty more great ideas and a promising career ahead of her.
I also think it's great that so many people these days are able to launch their careers via their personal web presence, build up a fan base, and then gain official representation and publication by a traditional publishing house. The Coquette did it as well, and I think the way is being paved for many other creative types to launch their careers this way. It's also cool to have followed these people when they were just getting started on the web and finally see them get published.
From a publishing perspective, graphic novels (or any other book with a nontraditional format) are harder to sell, and so most agents are reluctant to acquire them. But I think graphic novels are rising in popularity, and the general public is becoming aware of them as not existing solely for the "geek" community or hardcore comic fan (not that there's anything wrong with the geek community; I myself am a card-carrying member). The visual element adds a rich layer to the storytelling that just can't be achieved in a standard novel. Look at the success of the Scott Pilgrim series. The creators of Avatar: the Last Airbender series had great success continuing their stories in the graphic novel format as well. I hope graphic novels continue to get the exposure they deserve, and with the changing nature of the publishing industry, I think graphic novels are only going to do better from here on out.