So, a gay space biker book. Not my usual. The biker part at least.
I do notice that I have a few archetypes for female characters in my head. Zarya Overwatch or that buff robot woman from Questionable Content, a friend of mine if on the skinny side, And Mokoto Kusanagi's haircut.
Margot came up as Zarya, but as I read, I don't think that's it. She's ex navy, but sounds more with the sliders in the middle, with maybe the buff one a little higher.
My first thought was she's short because being on an enclosed naval [space]ship would probably warrant being small, but given that she's a "Lunatic", (person from the Moon, love the name,) maybe she is tall.