IMO You shouldn't try to be friends with someone you want more then 'friends' with. You can only pretend so long before you are emotionally stagnating yourself from moving on. You're moving away in 4 months anyway. Just ignore her and only say hi to her if she says hi to you first. Don't waste anymore time or emotional energy wondering or obsessing about her or what she's thinking/doing. Soon enough you'll be gone and you'll much easier be able to get to the stage of indifference to her.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion