Been talking to a girl and feel like i'm leading her on?

i don't know how to keep things casual. i don't talk romance, but i really get to know her. we get along great, but i don't feel romantic urges (and by that, i do NOT mean ). i mean genuine feelings of infatuated attraction. at the same time, she's the most stable girl i've ever met. to other girls i feel more naturally drawn to, but they lack the lasting qualities of this one. i just don't think it's right what i'm doing. i'd like to fall in love with this girl, but i can't seem to have my heart follow. she's the best, but not the girliest. am i just nervous and using this as an escape mechanism? we often stay up way too late talking on the phone. she feels like a good friend, but not someone i'm irresistibly drawn to. i also wonder if i'm doing this (getting close to her) because it's the only thing working out.