Friend is obsessed with computer?

My best friend is staying over at my house for a while and she is constantly on the computer. She is on forums and chat rooms from the time she wakes up until after everybody else in the house is already asleep. The shortest time she has been on the computer was For maybe 6 hours. Whenever I try to talk to her she acts like I am not there and she constantly separates herself from others so she can be alone on the computer. One time she told me she made a house on the sims and I said"that's cool can I see"and she said no cause she wanted to be alone even though she was alone all day. I told my sister about this and she said I should give her some space but I hardly talk to her at home cause she separates herself from me to be on the computer. Sometimes i wonder why she even comes to my house if she is going to stay on the computer 24/7 What should I say to her so she can possibly stop this besides to never invite her over again.