Hmmm. Old Iron is adding to shipgirl canon, and throwing some very blatant Jane-hints.
Shipgirls can learn to control their weight better.
Jane specifically references 'Her' radar.
Then we see Jane carefully hug her father, noting to herself she will have to be more careful in the future.
One assumes that a shipgirl who was born and raised human would probably have very good control of her weight.
It seems to me that not only is Jane a shipgirl or possibly even a naval base personae, but she knows she is.
Has Victory been having talks with Jane that the authors haven't been telling us about?
And... If Jane is the personification of a naval base, perhaps she is the limiting factor for the size of the US fleet? As she grows and matures, more shipgirls will be summoned / born.
This might explain her secrecy. She knows she's vulnerable at her age, and isn't telling ANYONE.
This is all idle speculation from someone who knows nothing, but enjoys guessing