Girls, please check this out!?

So i have a summer job as a lifeguard that Ive been doing for a handful of summers. well i mean theres this girl that ive wworked with there for a few summers and I'm two or three years older than her. we were talking alot and it was really easy to talk to her and I really want to hang out with her maybe go see a movie or just chill. I know what i want to say, just not sure how i should do it, since we dont work together much. any suggestions. I have her number from work (not to sure if i should tex her thou), and we are fb friends. but idk any ideas would be great, thanks!