I'm feeling REALLY frustrated with my sister at the moment.

She constantly asks for my help, opinions and advice. She says all the right things, she wants help, she needs it, she goes to the doctors surgery and ticks all the boxes, BUT she never actually takes my advice or listens to what I've said.
Then a week later she'll be complaining about the same things which I find annoying and really quite ignorant.

*Why do I, and why does she constantly waste my time? Is this her reaching out for help? Wasting my time for the attention or sympathy?
Don't get me wrong, it's not just my sister. I've actually come across many friends who act in a similar way and I find that just as annoying. I'm starting to wonder if this is something people do when they want help, but not enough to take steps in the right direction? Or if it is as simplistic as wanting or needing attention? Validation for what she's feeling?

As annoying as I find it, I still want to help. Is there a way of breaking through this behaviour to actually help her? Or is this behaviour, when indulged, could only get worse? If it's about validation I'd be happy to help, and continue to offer my support, but I can't do it all the time. Especially when it's the same problems over and over again. I'm exhausted.