This sound is from Mabel Pines - Gravity Falls Soundboard

Mabel Pines (born August 31, 1999, 5 minutes before Dipper Pines) is one of the two main protagonists of the series. She is a 12-year-old girl spending the summer with her Great Uncle Stan in Gravity Falls, Oregon, where she and her brother frequently encounter the supernatural. She takes a much less serious approach to life than her twin brother as she navigates her way around odd, new surroundings.