Milez Das’s review published on Letterboxd:
Colleen is called back from her nun duty by her mom since her brother is back. As we take this journey with Colleen, we see her relationship with her mother, why she decided to become a nun, her bond with her brother. The little things she likes, the smile she has that makes everything okay and the goth, metal and past phase of it.
We see Colleen looking back at the videos made with her brother. The nostalgia she goes through. The beauty of the movie comes through when she tries to cheer her brother up. Going back to the goth phase of her life, coloring her pink, putting on black lipstick, make up. Then dancing on tunes. Taking a walk, talking about her experiences as nun.
There is a strain in her relationship with her mother. Even though they both love each other very much, the suicide attempt by her mother has taken a toll on Colleen. Then, her parents taking doing weed. Colleen just wanted a structure to her life.
You can see how her mother tries to make the last moments with Colleen before she leaves to take her vows. Everything here is beautifully, dark and everyone just trying their best to do with whatever they can.
Addison Timlin is just an revelation here. I have seen her in many roles previously like in Californication or That Awkward Moment. But here as Colleen she just surprises you in every way possible. She is funny, cute and that smile is to die for.
Little Sister is about love, structure, nostalgia and just trying the best we could.