When the elders go to the Fram at night, Susan says almost hopefully We may meet Mrs Jackson but Mrs Jackson was far away (playing whist in the village, and) trying to remember who was trumps. Then Susan says We'll meet the Jacksons milking when we come in. They decide to return with the brats Titty and Roger, and Mrs Jackson says Eh, what's this ..... And you not in bed. This is no time to go walking .... off to bed with you (WH18).
Later when John, Susan and Peggy set off at night on the rescue expedition, she just says Don't you go too far .... You won't be long. If it was Mrs Dixon they would probably never have been allowed to set out. But Mrs Jackson's mind moved more slowly and she says Funny I never saw them go (WH25). At the North Pole the next day Captain Flint said .... there was Mrs Jackson like an old hen who'd lost her chickens to say that all her lot had gone out and never come back (WH29).
In Pigeon Post the entire group including the Swallows are initially camping in the Beckfoot garden until Mrs Walker comes to Holly Howe, as Mrs Jackson has got visitors for the next two weeks (PP1). So they .... won't have Swallow until then (PP2; implying that Swallow belongs to the Jacksons).