Non-PRO English Social Sciences General / Conversation / Greetings / Letters

This is from Orwell's Coming Up for Air.
The narrator of the novel is reminiscing his childhood in the English countryside at the turn of the 20th century and talks about an older girl (hired by his mother) who used to take care of him and his brother.

"Poor Katie! She had her first baby when she was fifteen. No one knew who was the father, and
probably Katie wasn’t too certain herself. Most people believe it was one of her brothers. The
workhouse people took the baby, and Katie went into service in Walton. Some time afterwards
she married a tinker, which even by the standards of her family was a come-down. The last time
I saw her was in 1913. I was biking through Walton, and I passed some dreadful wooden shacks
beside the railway line..."

How should I take this "going into service"? Does the author mean something like a correctional institution? "Walton" seems to be Walton-on-Thames, an ordinary English town not far from the settlement of the narrator's childhood, but there doesn't seem to be any relevant information about the place.