Friend is so desperate for marriage/children she’s dating an unemployed drug addict

My friend has been dating her bf for over 2 years and he hasn’t worked the entire time they’ve been together and is not actively looking to find a job. On top of that, he gets high every day.

She constantly expresses how unhappy she is and how frustrated she is with her bf but never makes any changes. I really think deep down she’s so desperate for marriage/children she’s willing to put up with it but I’m at a loss on how to even be her friend at this point? I can’t support this relationship but if she’s unwilling to make changes what do I do?