Simplify the following text for a Grade 11 native English-speaking person.
Original: A pilot episode for another Doctor Who spin-off series , K-9 and Company , made in 1981 , featured Sarah Jane and the robot dog K-9 ; however , a full series was never commissioned .
Simplified: Sarah Jane was considered the most popular companion of the Doctor and appeared in the new series episode `` School Reunion '' along with her robot dog , K-9 .