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This one is going to be a real longshot. I've only read a couple parts of the story, and I only remember a couple of moments from those parts of the tale. Hopefully they will be memorable enough for it to be identified.
The protagonist in the story is a human female soldier who fights on various planets as part of mankind's ongoing military campaign (against who or what, I do not remember). She wears advanced, powered combat armor and carries very advanced weaponry.
I also recall that the protagonist may have been gay. It sticks in my mind she has a girlfriend who is a fellow soldier, though assigned to a different vessel, and they spend long periods of time away from each other. I believe there was a paragraph where the protagonist arrives at a base/starport, and finds out her partner shipped out just a few hours earlier.
The first specific detail I can remember is a battle where the protagonist is seriously wounded. She is hit in the lower leg by a powerful enemy weapon. The weapon's blast penetrates her armor, and mangles the lower leg off just below the knee. Her powered armor immediately activates its triage protocols. A razor-sharp iris-valve located in the mid-thigh amputates her ruined lower leg, while other systems inject her with painkillers and other medicines to keep her from going into shock. I believe that is the final scene in the first part of the story I read.
The second detail I recall comes from the second part I read. The protagonist is sunning herself on the beach with her partner, both of them enjoying a couple weeks worth of shore leave. The docs have grown her a new leg. The protagonist states she still has some therapy to do before she gets full use of the limb back, but that she will be back in the fight soon enough.
Timeframe of Publication
I'm thinking this one is from the 1970s. I remember reading both parts in a couple of old sci-fi magazines that my dad had picked up at a used book store. It might have come out in the early 80s, but no more recent that that, IIRC. I don't think it would been published earlier than the 1970s.