I have been talking online for a year now to a girl I barely knew in high school. Should I call her?

For almost a year now I have been talking online to a girl I knew in high school. She lived right next door to my best friend, but she and I barely knew each other. Somehow we started talking on Facebook about a year ago, and have been exchanging messages and IMs about a lot of different things. Some of her messages are really long, and it seems like maybe she likes me. Apparently we have a lot of interests in common. She gave me her phone number so I can text her, but I am not sure if she wants me to call. It just feels awkward because some of her close friends are people who don't particularly care for me, and we've never really had a cl together or hung out or anything. How should I approach this so that I don't mess up things?