Maybe she's having FUN.

God knows my friends and I did ... we LIVED and are still LIVING our 20s ...

It's so much fun to study, work, travel, drink, get wasted, have late nights ...

Your friend sounds like she is making the MOST of her life ... you only live once ... as long as you are forward focused enough to achieve, then balancing the working life with partying is completely acceptable.

I am 28 and i have my PhD. but i spent years partying - drinking and drugs - and i do not regret a second of it. i know that when i have children i'll be such a great mother because i will understand what they are doing ... i'll probably have done much worse!

your friend deserves some respect for enjoying herself in the prime of her life. your post sounds like you are a little jealous - i understand you have a lot to deal with, but let others have fun if you don't feel comfortable then hang out with people who you DO feel good being around.

good luck