Affiliation: Order of the Phoenix
House: Gryffindor, 7th Year
Harry Potter and the Deathly Hallows is a big book for Ron. In it, we witness our friend's best and his worst. Ron hits some terrible lows, but he redeems himself quickly and emerges as a true hero. And, to wrap things up, many of the seeds of his character that were planted in earlier books start to blossom here (forgive us our poetic waxing). What we mean is that the things we've seen or suspected in Ron earlier – like his fear of inadequacy, his uncertainty about his role in this quest, and, of course, his cauldron full of hot strong love for Hermione – all come to the forefront here, and all get resolved.
The biggest struggle Ron encounters is his lack of self-confidence. In all of the Harry Potter books, poor Ron suffers from being overshadowed, particularly by his successful older brothers and by his rich, famous best friend, Harry. Ron's fears are given voice by Tom Riddle in the Horcrux locket that Ron has to destroy once he returns to the quest:
"I have seen your dreams, Ronald Weasley, and I have seen your fears. […] Least loved, always, by the mother who craved a daughter… Least loved now, by the girl who prefers your friend… Second best, always, eternally overshadowed." (19.108-110)
In Chapter 19, we see that Ron's insecurities mostly boil down to the following:
But Ron's growth isn't over when he destroys the locket; he still has to work through his love for Hermione. We've seen it coming for, like, four years, but it's still been tough for him to come to terms with. After all, Hermione's always been a friend – and here, he finally is ready to admit that he wants to be more than friends. He and Hermione don't share their first kiss until the climactic Battle of Hogwarts, but it's a memorable one. We've known for a while that these two are meant for each other, and it's great to see them finally together!
In the Epilogue, we see a grown-up Ron married to Hermione and sending their daughter Rose off to her first year at Hogwarts. So we know that everything worked out for Ron exactly as we hoped it would. But, in case you want to learn a bit more about what happens to Ron, here's what Rowling has to say:
Harry and Ron utterly revolutionized the Auror Department in – at the Ministry of Magic. So they – I mean, they are now the consummate – they are experts. (source)
We're not surprised.
And, to top it all off, Ron finally gets some of the recognition that he craved as a boy. In a 2007 interview, Rowling was asked if Harry and his friends will ever end up on chocolate frog cards. Rowling responded, "Definitely, and Ron will describe this as his finest hour." (source)