Minister for Magic from 1827 to 1835. She was more appreciative of Muggles and their technology than many wizards of the time, and thus introduced the Hogwarts Express as the method of transport to Hogwarts (Pm).
Ottaline Gambol personally offered the Hogwarts Express trolley witch the job she has held ever since the train started taking students to and from Hogwarts (CC1.11).
Other canon notes and references
There is possibly a family connection to the joke shop Gambol and Japes in Diagon Alley.
The Hogwarts Express trolley witch felt she had fallen short of Ottaline Gambol's hope or expectations after Scorpius and Albus escape from the train (CC1.17).
Otters are Rowling's favorite animal (source: Twitter).
"Gambol" means to frolic or romp (Otters are very playful.).