Something I appreciate about Amy’s storyline: she gets married and continues to travel on the TARDIS as a companion.
This was pretty new to Doctor Who, because in the classic series, “companion meets someone and stays behind to get married” was one of the most common reasons for a companion departure, starting right away with the first one: Susan, the Doctor’s granddaughter. There, it was a clear signifier that she had grown up (despite supposedly being, like, 15), and needed to move on. But then it happens again, with Vicki, Jo, and Leela; meanwhile, Peri is revealed to have actually married someone, and Mel runs off with a lover. These storylines were never afforded to male companions: Steven helps restore peace in a society,Jamie’s (and Zoe’s) memory is wiped, Harry decides to stay behind, Adric dies, Turlough goes home. Sure, female companions did leave for other reasons, and I don’t want to overlook that. But clearly, marriage was something not compatible for the TARDIS life. The adventure’s over, girls.
As such, the ending of “The Big Bang,” with Amy in her wedding dress waving goodbye from the TARDIS, is an important step forward in Doctor Who’s history. You can be married, have adventures, and wear miniskirts while you’re at it. This is consistent with Amy’s personality and not something for everyone, of course, but it’s a change. (It’s Rory, a nurse who years for domesticity, who sometimes represents the traditional feminine.)
Yes, the TARDIS life does end up interfering with their own lives as they move forward, but it’s not simply because they are married. It became too dangerous to risk…Rory died many times, their baby was stolen and Amy traumatized. The Doctor, who couldn’t leave them alone out of love (and they couldn’t leave him, either), was causing more harm than good and that was taxing for that point in their relationship. And that’s what culminates in “The Angels Take Manhattan,” where even if the Doctor could find some way to retrieve them, he probably shouldn’t and just let them carry on with some stability. And, well, that’s what happens with relationships (including friendships) sometimes, regardless if there are time travel shenanigans, and regardless if there is a marriage.