Thank you for pointing out that constantly listening to music makes it really hard for someone to approach you and say hello. My young friends all say I'm crazy but you have VINDICATED me!
Wave politely in her field of vision and make eye contact so she knows you want to speak to her. Wait for her to take out the earphones. If she tries to talk to you with the earphones still in, make the "please remove your earphones" gesture. Maintain a pleasant smile the whole while. When you have her attention, tell her you see her at the station all the time and you wanted to introduce yourself. Tell her your name. Ask what music she's always listening to.