How do I (20F) help my friend (20F) after a “breakup”?

Hi, sorry English is not my first language.

I (20F) am not living in my home country for my studies, and I am living with my long time friend (20F) I will call Mary.
Mary has a boyfriend back in our home country and they are in a long distance relationship (more than 3 years, very serious). They recently had a very heated argument and, her boyfriend decided not to come (he had a flight today but ended up not taking it). We don’t have any news from him so she is devastated and doesn’t know what to do. She is going to sleep right now at 7pm because she wants to wake up tomorrow feeling like everything was a dream/nightmare.

How do I make her feel better? How can I make her think of something else?

Thanks for the help