Just because someone asks for your perspective doesn’t mean they are bound to do what you tell them.

When someone asks, I will give my honest opinion. The people I'm closest to get the truth full blast. Others get a carefully considered, fact-driven articulation of my perspective on the reality that person is dealing with. I generally don't hold my tongue if there's something I think someone needs to hear. I will attempt to keep things nuetral and nonjudgemental. Then it is for them to do or not do. Expecting anyone else to do anything for any reason is destined to lead to disappointment almost all of the time. I have accepted this and it's quite liberating. Dealing with those who have not yet taken responsibility for their lives and their choices can be quite exhausting and exasperating. Or infuriating. If this is a freind, someone you care about, don't be so quick to withhold your support and freindship. Share your concerns honestly, but realize this friend has the right to live her life the way she choses.

No, I always view my efforts in terms of a file cabinet. The information goes into a file folder and at some point in time it will be deemed necessary.

Why do you care?
It's always best to mind one's own business, unless asked, then just give your advice and move on.
No time to worry about others if you are busy with your own life and love interests.