Sorry to hear about this sad loss, its never easy with such a sudden passing of a close friend & a brain aneurysm can happen to just about anyone at any time, no matter what the age. My best wishes go to all her family & friends, sounds like she lived life to the fullest.
Thats sort of how my fiance passed away, she had a brain hemorage during an emergency cesarian, aged 22. You just never know.