Mentha was seven years old at the time when the Ruffians, led by Bill Ruffin, invaded the Shire and imprisoned a number of Hobbits that were enslaved for nearly a month. Mentha was freed with a number of children and took shelter during the Battle of Bywater. She later attended Bilbo's farewell party on September 12, 3001 3A.
Later, Mentha and her family joined the Shire Company under the leadership of Will Whitfoot when Sauron was preparing to unleash darkness throughout the corners of Middle-earth. She received a Barrow-blade from the Maiar Tom Bombadil, who saw a lot of courage in her. Mentha would participate in the Battle of Pelennor Fields where she took down about twelve orcs that were retreating from the battlefield. She later fought in the Battle of Morannon against Sauron's forces and give Frodo a chance to destroy the One Ring. She and Merimas were both slain when they were defending their younger sister.