In April 2012, she posted her first photo to Instagram with the captioned reading "Easter breakfast with the crazies!"
She can be found on both Twitter and Instagram by the handle brynleyarnold. She has worked as a Registered Nurse.
Lindsay is not the only dancer in the Arnold family. Brynley's sisters Rylee and Jensen also dance. All four sisters run the collaborative YouTube channel The Arnold Sisters. On October 9, 2020, she got married to Donny McGinnis.
During season twenty-one of Dancing with the Stars competition, she posted photos with her sister and her sister's dance partner Alek Skarlatos.