I am sorry that you are going through this at the moment. You clearly care a lot about your daughter and that shows through your posts. I have read through your previous thread and I am not surprised that you are exhausted.
Disimpaction when a child is really very constipated is difficult. It can be a long winded process but in most cases a combination of a lot of movicol and in some cases a few enemas will eventually result in a bowel movement. While it may seem like you have given this a try from my reading of the last thread you have only been giving the higher doses of movicol at max for a couple of days (as before you were struggling to get her to take them) and she has only had one enema.
I don't think that this discussion of her being septic is hugely helpful. She has been examined by multiple doctors in the last 24-48 hours and has had her temperature, heart rate, breathing rate etc. None of these things have indicated sepsis (which is a specific diagnosis) or they would have acted on it.
I am also not entirely sure that pushing for an abdominal x-ray is going to be helpful. They know that she is very constipated (up to her ribs) and as long as she is passing wind (meaning that she isn't obstructed (completely blocked)) what they see on the x-ray isn't going to change treatment.
If I were in your situation I would ask to wait to be seen on the consultant ward round (paediatrics is one of the specialities where there will be a consultant going round every day). Explain that you are worried and that you aren't coping with doing this at home on your own. Ask if they can admit her to do it in hospital. This would mean that she can be monitored so that if she did get worse they could act on it quickly and also that you could get some support from the nursing staff who will have done this before. You could also ask whether a medication like buscopan (if she hasn't had it before) is suitable in her age as that will help with the painful cramps that she is having.
I agree that being firm in expressing just how worried you are is good and also pushing for admission so that she can be monitored while they try to get things going is a good idea.