Greta Gerwig's Little Women adapted Louisa May Alcott's coming-of-age story about innocence and empathy into a feminist tale for the 21st century, and according to critics and audiences alike, she nailed it. True to the metafictional style of modern cinema, and in response to more than a century of debate regarding Alcott's own ending, Gerwig left moviegoers to wonder whether or not Jo and Professor Bhaer actually marry. Jo consents to let her heroine have her moment under the umbrella with the professor, as is the case in most other versions of the story, but only on the condition that she retains the copyright to her book and a fair share of the royalties.
Alcott herself wished Jo became a literary spinster, but the love story has still somehow stood the test of time. In a daring departure, Gerwig leaves Jo's fate up to the viewers. Does Bhaer take a teaching job at Jo's school and marry into the March family? Or does Jo stay true to her word and maintain her familial freedom? There is evidence to suggest both are true, opening up a conversation about the value of each ending.
When Jo learns Aunt March has left her a grand house, she decides to make the most of her inheritance by opening a school on the grounds. True to her character, Jo develops into the kindhearted, charitable woman Marmee has taught her to be, and she does not need a husband to do it.
Since Jo intended to open a school, it's likely the final scene in which she and her family celebrate Marmee's birthday on the grounds is reality and not just a part of Jo's story. And considering the conservative culture of the time, it's unlikely Bhaer would have been present if Jo had rejected him.
Jo and the professor share an admiration for each other early on in the film. Mirroring Alcott's narrative, they maintain a flirtatious relationship while living together at the boarding house in New York.
By the time Bhaer comes to visit Jo, she has established herself as a capable, independent woman who not only finished a novel, but has resolved to open and run a school with her inheritance. Gerwig makes it known that Jo does not need a husband, and her loneliness even appears to have been cured by Laurie and Amy's return.
Bhaer, however, impresses the March family, and even Jo is disappointed when she learns that he plans to move west. Prior to her conversation with Mr. Dashwood, the editor, Jo's affections for Bhaer are clear, and because she is already well off in her career, it's entirely possible that the literary spinster could fall in love without sacrificing her independent spirit.
Aunt March leaves her lavish mansion to Jo, who, true to her character, turns the property into a grade school for children. At the end of the film, we see Jo walking through the grounds with a cake to celebrate Marmee. As she goes by the children learning to paint, she affectionately lays her hand on Bhaer, who appears to be working as a teacher.
Bhaer joins the family in their celebration, and his presence in the March family affairs suggests he and Jo did, in fact, end up together. Considering the culture of the 1860s and the fact Jo marries her heroine to Bhaer's counterpart in her story, the couple likely would not have been together if they had not wed.
Jo makes her desire to stay single adamantly clear to her friends and family over the course of the film. She is upset when she learns John Brooke wants to marry Meg, and maintains her childlike attitude for as long as she can justify it. She even rejects her best friend's proposal because she is not willing to settle with him. Therefore, it is a surprise to learn that Jo would give up her independence and her freedom to marry anyone.
Since Bhaer has nothing to tie him down and nothing to offer Jo but his companionship, he would be able to slide into her life without asking her to sacrifice anything. Jo and Bhaer would almost switch social roles, with Jo being her family's main financial support while also maintaining control over her choices.