When first finding your work I was positivly shocked and quiet happy to have found a different Lara, in this case your Lara. Reminds me of the good old Pre-Reboot Croft.
Your ideas were hitting the spot too. I think a Croft has to be crafty to achieve their goals. In this case Lara getting what she wants, her way.
I posted my idea in the comments before this thread was created which was loosly based on Lara Crofts Lore/background Story at one point. She had some military experience with some "Commandos/Marines", but I never got what kind of branch it actually was.
How about her visiting some Royal Marines/ British Commando Cadets in some relieve/R&R typ mission. Maybe she knows her old Drill Instructor too. Could be anywhere.
Those young guys/boys might be worth her time and willing/able too and she would give them hell with her idea of a training course/session.