There are a few pieces of advice that held me in good stead from the time I was a child through adulthood. I'm grateful I learned them then. Sometimes I need a refresher course. I also realize many adults never learned anything close to this. Too bad they didn't learn it as children, it would help make the ride smoother.
Accept it or change it.
This is huge in most situations that don't agree with you or your goals. My children can slip into their complaining modes, whining about something gone awry with a friend, in class, or at home. I remind them to quit telling me the problem and let's talk about the solution. They are learning that in almost every situation they have two basic choices: Accept how it is and move on; or change the situation, feeling or outcome. If they are not willing to take action, they have to be willing to accept that's how that "thing" will remain. And, they have also learned that just because they want to change it or try to change it, it may not actually change. At that point they accept they've done all they can and it makes them happier to then have to accept it.
My role? I have to remember that sometimes they complain and vent to get empathy from me or just a big hug. They don't really want a solution.They are nine and six, after all. Sometimes talking it out lets the steam out of the situation and a big hug patches it up and they can move on to something else. I've also learned that this part doesn't stop when they stop being children. Some adults just need to vent and let off the steam to move on. They don't want a solution - acknowledging the frustration is enough for them. But, if they continue to harp on it, then it's time to invoke the "accept it or change it" tactic. Enough already with the whining and complaining.