There is this exchange program where students from another country come and get to experience school in a different place and visit other places and attractions. The students came to my school and I'm one of the students in charge of being the buddy for one of the students. She (the student) basically just goes with me to my classes but has the option to go to other classes as well and I can answer any questions she has. We get along really well and she is really nice in general so I didn't really think of the possibility of her liking me. But I've noticed that she always laughs a lot at my jokes even the ones that aren't that funny. One time in particular, she came up to me when I was with my friends and reminded me what class I had next (I'm kind of forgetful and don't even have my timetable memorized yet). I just responded "Oh yeah I forgot" with a smirk and she started dying of laughter and even snorted. Then when she walked away one of my friends said that he thinks she likes me. Also when we text each other she sometimes adds a bunch of letters at the end of my name or other words. Not really sure what to make of that though. So it's kind of been on my mind a lot recently as to whether or not she likes me and if I should ask her out.

However, she is leaving at the end of the month and it's extremely likely that I will never see her again. So I'm wondering whether or not I should ask her out at all only to have a 2-3 week relationship and I also don't want to ruin our friendship and make the remainder of her time here awkward in case she doesn't like me and I ask her out.

tl;dr: Girl from another country is at my school and I think she might like me but she leaves at the end of the month.