As moms, our family is our number-one priority. This means things like TV shows, trips to the gym, and even personal hygiene sometimes take a backseat to the needs of our partners and children. One thing you should never sacrifice, however, is friendships — especially the one with your BFF. Whether she's a fellow mom or free from children, a best friend knows you better than anyone, making her your strongest support system. She is the one person who won't judge you and will always reassure you that everything will be all right. In honor of National Best Friend Day, here are 18 reasons why every mom should be thankful for the special gal pal in her life.