I just want my kids to be happy!!!

So as a mother I really just want my kids to be happy! but, of course there is always a but. I can not make them happy. They have to figure out how to just be happy. I try very hard to be a good mother. I know I am a good mother not a perfect mother but my kids know I love them and I never ignore them and I try to give them what they need. Mostly I just love them...and I spend a lot of time with them... Still how do you make sure you've done what you should? I know some kids who are so confident in themselves and I wish I could give my kids that. Confidence goes a long way and even kids in the same family one will have it and another will not. So how do you give them confidence? That is the question I most want an answer to....