From my experience with the online thing, first, you need to get this girl on the phone as quickly as possible.
After you've made initial contact with a girl online and you've exchanged emails, you have to get her on the phone ASAP because girls, especially attractive girls, get literally hundreds of messages from guys on a regular basis (especially if she has a really hot picture).
If you don't get her on the phone quickly, you'll get lost in her mind with all the other guys.
Based on the message she sent you, this is what I would say to her, "What's up. I'd like to talk with you but I'm not really into emailing back and forth. I'm usually on the move coming in or going out somewhere so I don't always have time to sit at my computer but give me your number and I'll give you a call.
Now, by responding this way you are telling her a few of things.
1) I may want to talk to you and get to know you better but I already have an active, busy life so I don't really need you.
2) I'm not desperate.
3) I probably have other girls that are already occupying my attention and you have competition if you are really interested in me.
4) Give me your number and I'll give you a chance to earn a place in my harem of chicks.
5) I have a real life and don't have to sit at home all day emailing your a$$ back and forth.
6) I am probably a fun guy to be with and my life is probably very interesting and exciting.
If she is really interested, she'll respond with her number.
If she is bullsh*ting you or looking for some email pen pal, then most likely you won't hear from her again.
Either way, you'll know what the real deal is.
