I never looked or thought of Lilly as a pretty or attractive character, but she just doesn't seem to struck as such.
Despite losing her father, what she did to Carley/Doug is unforgivable and so she was left on her own. Couldn't care less if the walkers devoured her.
As for Molly, she reminded me of Desmond from Assassin's Creed (running and climbing walls/buildings across the cities), which was kind of pretty cool. :)