How old was Thalia when she became a tree?

In Greek mythology, Thalia was one of the nine Muses and the Muse of comedy and idyllic poetry. According to the myth, Thalia was turned into a tree by her father Zeus to protect her from harm. There is no specific age mentioned in the myth regarding Thalia when she was transformed into a tree. The focus is more on the event itself and its significance in the story rather than her age at the time.