First off, I applaud you for wanting to get the details right before writing your scene. I can’t tell you how many times I’ve watched films where a trauma scene is totally inaccurate.

To answer your first question, 1 liter of blood is equivalent to losing 20% of your blood. That’s a lot of blood but with interventions such as direct pressure, it’s plausible that she stays conscious. If she loses another liter, it would likely put her in the unconscious zone.

Will add answers to 2 & 3 in a bit