‘Hekinah Degul’ means something like: ‘His flag is erect!” in colloquial Lilliputian.
Clearly, Mary didn't need to translate this into English in her memoir, since she had mastered Lilliputian.
Luckily, Lemuel Gulliver, in his 'Voyage to Lilliput' (1726) was careful to translate into English all the Lilliputian words he inserted into his story, so that I was able to learn Lilliputian myself, and to translate Mary's Lilliputian into English.
(See Lilliputian Dictionary in the Menu, under More)
(L to R) Lemuel, Reldresal, in a Lilliputian Language lesson.