Terry made her first stage appearance at age nine, as Mamillius, opposite Charles Kean as Leontes, in Shakespeare's "The Winter's Tale" at London's Princess's Theatre in 1856. She also played the roles of Puck in "A Midsummer Night's Dream" (1856), Prince Arthur in "King John" (1858), and Fleance in "Macbeth" (1859), continuing at the Princess's Theatre until the Keans' retirement in 1859. During the theatre's summer closures, Terry's father presented drawing-room entertainments at the Royal Colosseum, Regent's Park, London, and then on tour. In 1859, she appeared in the Tom Taylor comedy "Nine Points of the Law" at the Olympic Theatre. For the next two years, Terry and her sister Kate toured the British provinces in sketches and plays, accompanied by their parents and a musician.