Season 6 is completely about growing up. Growing up doesn't necessarily mean making all the right choices, but learning how to make good choices by making bad ones and learning from them. Which they all did.
I agree with...
To me growing up just means having to make difficult decisions, rather you choose wrong or right. You can still grow up and act immaturely at times. Really growing up is learning from your mistakes and I think Buffy and Willow both did that, so did Anya and Xander. Buffy leaving Spike, Willow going away to England, and Xander realizing he wasn't ready and Anya having learn how to deal with real pain. Imean they went through a lot of serious shit...maybe you have to grow up a little.
By the end of the season they all come to an understanding about what changes they need to make and they've realized the error of their ways.
Xander realizes he should have been honest with Anya from the beginning about his reservations about their marriage. He tries to make amends and see if there's a way they can work it out, but she doesn't want to go back to just dating. Either way, Xander has still grown up cause he's learned he needs to think things through more and be honest with the people he loves and with himself.
Buffy finally realizes that taking care of Dawn doesn't just mean shielding her from the world, but showing her the world. Not just sticking her with a babysitter but spending time with her and being the sister, friend, and role model that Dawn needs. She also has given up her unhealthy relationship with Spike, despite the feelings she does have for him.
Season 7, the first episode in fact, is basically a showcase of how much they've all grown.
Willow has spent the summer in England with Giles learning to accept that the powers she has inside her will always be there, but learning how to control them and not let them control her. The very fact that she was able to come back from such a dark place and try to get help shows how stong she is and that she's grown up a lot. She's still grieving over Tara's death, trying to get over a strong addiction, facing the guilt of the horrible things she's done, and not knowing if she'll even be welcome back home by her friends. Yet, she's staying strong and determined and all throughout the season she shows that she's being a lot more careful with her magic and that she's learned from all her mistakes.
Buffy is teaching Dawn how to fight and letting her be a part of the things she used to hide from her. She's more involed in Dawn's life and even takes a part-time job at the high school to keep an eye on things and make sure she's safe, even though she is still working at the Doublemeat Palace and has her Slayer duties as well. Buffy has also come to accept that whether she wanted it or not, she's alive. She had to overcome the loss of being ripped out of Heaven, and has finally learned to enjoy life again.
Dawn has also grown up. She isn't as whiny anymore and isn't getting herself kidnapped everytime she leaves the house. She's still a teenager and makes mistakes, but compared to her character in Season 5, she has clearly matured quite a bit.
Xander finally got a steady and decent job, bought a new car, and has been looking out for Buffy and Dawn. He still loves Anya, but he's trying to move on while still having to see her on a pretty regular basis. Even though it's hard for him being the only one without any superpowers, he keeps fighting and does everything he can to keep everyone together and diffuse fights and keep everyone going.
They all still make mistakes of course, cause not matter how old you get, you're gonna screw up sometimes. But from where they started in the beginning of Season 6, it's evident they've all grown up a lot.
