Please can someone please give me some advice on my new Royal Python not feeding?

Have been trying to feed her once a week from day one, so really perhaps I haven’t given her enough time to settle in, especially as she shed in her second week with me. Many books mention that exposing the brain of the mouse often works, but I was hoping not to have to resort to this revolting task just yet! Does anyone have experience of this practice actually working and if so should I attempt this on my next feed or wait a few weeks longer?

As others have said....

First, separate them. Put the female in her own enclosure and leave her there for a week with no interaction. Only change her water. Then offer her one live mouse. A year old female should not weigh only 200-something grams.

So that anyone with more experience than I can see if I have also been mislead about the age of my snake, I have added pictures of Lilith (and one of Monty) to my profile. I have entered one picture taken in good light, which shows that she still looks in pretty good condition, despite the lack of feeding. I have added a further picture of Lilith being held, so that her size can be gauged against the size of a hand.

Seperate them, permanently, (except for breeding later)
give her atleast a week to adjust to her seperate enclosure, try offering live prey, 5-10 min, then remove, try again in 4-5 days.
I have had luck by using loosely crumpled newspaper, packed in the snakes enclosure. The mouse will tunnel through it, the snake will usually follow the sent, this gives the snake a sense of hunting and will sometimes trigger a feeding response???
I have had new ones not begin to feed for a couple months! 3 or 4 weeks is not a long stretch to be overly concerned with! Keep a close eye on physical appearance, keep fresh water, good temps and humidity.
Keep us updated on how she does!!!
Best wishes!

Very pleased and relieved to report that Lilith took a defrosted desert mouse, heated up in warm water, last night. She had been offered two, but only accepted one, which is still a good start I suppose (she had only been fed one a week by the breeder I purchased her from).

I had, as you advised, set her up in her own separate enclosure. I am very grateful for all your advice. Regards Mark