I had similar requirements (1000 sustained lumens, not too bulky (slim profile), runs on 18650, etc.) to yours awhile back but quickly realised that all of those were not possible, at least not yet.
Armytek has some XHP35 lights that are single 18650, small, and sped'd at ~2K lm (1500 OTF). No idea about heat, step-down, run times, tint, or anything else. Guessing we'll see some similar ones coming out in the next few months.
I originally went with the MD2 M361 with high/low switch but it didn't work out as the light did not throw far enough for my intended use. Gene and Cathy were very kind and allowed me to pay the difference to exchange the M361 head for the M61Hot with high/low switch.
That was the perfect setup. Tighten the head for HIGH (sustained 500+ lumens) and loosen the head about a quarter turn for LOW. 500 lumens and 1000 lumens when compared side by side is just a hair less bright only and the throw is magnificent for its size. I got the clip as well for easier pocket carry when it is not in the holster.
It came back in stock. I have one on the way.
Secondly, if she is a white-wall hunter the squarish-circular beam profile might bug you a little but in real word usage it is not noticeable.
This is purely an on-the-job light - it's all about form and real-world function, not specs. It either works well and better than what she has or it doesn't. Of course personal preference on the look and feel is a big factor.
Most of the stuff we seem to want in our lights is irrelevant to first responders. They need simple, reliable tools in an urgent situation. It has to be predictable, reliable, and take some abuse.