Awoke Alone

Mentioned below is the use of lights. If the different lights show up as separate groups in the Lux lighting tab, then get the balance of each light correct, note the levels and stop the render. Go back to reality and set the relevant levels in the reality lighting tab and then rename each light group to be the same name. When you start to render again you should have all the lights in one group. The less light groups you have the faster the render.
What happens with lux render is that it will render a separate layer for each light group in the lighting tab, so for say 5 light groups you are actually rendering 5 separate renders at the same time... This will speed up renders, although Luxrender does take time to render, and so will most other render engines if they are physically based... fav.me/d7q1l75 not sure what your pc spec is, but it really needs to be multi core, and you also need the memory to ensure the scene can be held in memory. If you run out of memory then it gets cached to disc and that will totally kill your render times. Its worth opening task manager before starting the export via reality. Watch the memory usage for lux as the scene gets parsed out. Once the lux window appears with your image in it, see if the size has used up your ram... If it has, try removing any objects that are not visible in the scene to save memory (for example if she is wearing gloves, hide the hands that are inside, etc) The only other option is to use a smaller render size... Hope some of the info helps you get more out of Lux?