Firefly Lane. The TV series is based on Kristin Hannah's popular novel and stars (brunette) and Sarah Chalke as beloved best friends Tully and Kate.
Read Netflix's official description, below: "The greatest love story of all can be between friends. When unlikely duo Tully (Katherine Heigl) and Kate (Sarah Chalke) meet at age 14, they couldn’t be more different.
Tully is the brash and bold girl you can’t ignore, while Kate is the mousy shy girl you never notice. But when a tragedy brings them together, they are bonded for life—forever inseparable best friends.
Together they experience 30 years of ups and downs—triumphs and disappointments, heartbreak and joy, and a love triangle that strains their friendship.
Read more on glamour.com