When ya look at it she's really got just the three to cover travel in space an' dirtside. The lil' ones don't really get much use unless ya got a poor pilot or a real tricky dockin' situation even a good pilot could use the extra help with.
No one's got warp tech. If the Alliance was workin' on somethin' they ain't tellin' an' they'd just keep it to themselves anyway. [ But she's highly skeptical those dumbasses have it in the works. ]