@Nousher Ahmed,
Nousher Ahmed wrote:
"She appeared to be enjoyed herself, 'or so' the pigeons said. None of the animals ever mentioned Mollie again."
"She appeared to be enjoying herself, so the pigeon said." and "She...according to the pigeon" are about the same. It's just mentioning the source of the information.
"She..., or so the pigeon said" is casting doubt on the truth of the information.