Lonely, brave, kind, loyal, strong, tough, resilient, are all words that can be used to describe Rey. She is the hero of the Sequel Trilogy and grows immensely over the three film span of the new installments of the saga.
Rey starts out as a scavenger just trying to get by. She lives by herself and is awaiting the day her parents will return to her. She passes the time by rummaging through old Star Destroyers and trading scrap for food with Unkar Plutt at Niima Outpost. She eventually meets a droid, who leads her on an adventure that puts her in touch with legends of the galaxy and ultimately reveals the truth about her past.
Rey goes from a naive scavenger to becoming the last Jedi in the galaxy. She never backs down from whatever challenge that comes her way, no matter how terrifying it may be. She sees the good in Kylo Ren and does her best and eventually succeeds in bringing Ben Solo back to the light.
She overcomes the temptation to rule the galaxy alongside her grandfather, and with the help of the past Jedi, destroys the greatest evil in the entire galaxy. At the end of the Sequels, we see Rey adopt the name Skywalker in homage to her mentors Luke and Leia.
Throughout the Sequel Trilogy, she proves to be worthy of that name and a worthy heir to the Jedi.