I never assume pretension from you Robert, no worries there. I worry about the same things in my own writing, and analyze them to death. Sometimes it's helpful to have the outside opinion.
I realized overnight that I am way more familiar with female-oriented fiction myself than I would have assumed. I grew up reading Judy Blume and Beverly Cleary because I grew up reading anything that came within a twenty foot radius. Then I read Anne MacCaffrey, Ursula LeGuin, Margaret Atwood, Margaret Lawrence, Jane Auel, Mary Doria Russell and even, (gasp) Stephenie Meyer's Twilight series. That last was so my wife would have someone who knew books to talk about it with, and I am a very accomodating husband. I've even read a couple Danielle Steele novels with her (enough to know she's tremendously formulaic and predictable). Being married gives me even more insight, so maybe that comes in handy.
First -- working with what you have already (so much easier than starting over) is an arc concerning her upbringing. You have to show her being toughened up, because she comes across as assessing, detail-oriented, action-plan, initiative taking. Everything serves her purpose, there's no extraneous details. This made for breath-taking writing -- but it's not particularly feminine. Not that women don't plan or can't take initiative! But the mind-set is different. I've noticed that my wife's plans incorporate people -- how will this effect so-and-so? Do I need to bring this for say-and-say? How's that going to make so-and-so feel?
For example -- I shave my head down to fuzz because my hair-line is in a slow recede and I don't have time to figure out how to better style it -- same as the military, I just pragmatically assess and execute. My wife, however, has shampoo, conditioner, hair spray, hair gel, a straightener, a curler, several brushes and combs, elastics, clips and hair pins. She needs options. She has different moods. Sue seems more likely to shave her head than curl her hair -- how did she get that way? Because it's not normal -- but it's not implausible either. It just needs explaining.
Your Sue has the bad-ass driven nature of the Gunslinger on the way to the Dark Tower, utterly focused on a goal. She sometimes reacts to consequences to people after the fact, but my feeling with women is they worry about people BEFORE they take action. Action heroes are "act first, ask questions later and damn the consequences" but women incorporate people into their planning.
I am reminded of Sarah Connor in Terminator and Terminator 2 -- she transitions from damsel in distress to bad-ass rescuer. She might personify a lot of what you want to accomplish -- she trains the softness out of herself to protect her son. However, she maintains some of her femininity because her son is her primary concern. I'd watch those -- even just for the fun.