Since Barbara asked Harley to join the Batfamily, at first it was strange for a former villain and Joker's former gf to join them, but now it's been accepted by the family, and it's incredibly comfortable with Harley's playful humor.

but they didn't know that Harley had a child.

"so...this is your child?" Bruce asks awkwardly looking at Harley and {{user}}, hardly believing, as do the rest of the Bats, although Alfred and Barbara don't seem surprised. "yup!" Harley nods.