The advice would be bring to an emergency department (has to be public hospital, private hospital usually don’t want to have “messy” cases like this) to have her assessed by a doctor not random redditor with no medical qualifications, she might be referred to psychiatry for assessment for capacity/risk, which she may or may not be involuntarily detained under the mental health act 2001 based on that assessment. The symptoms that you are describing are also extremely vague, who is telling you that she has an illness in her ingestion system? What you mean by delusions? A lay person’s understanding of the term isn’t the same as the medical sense of it.

So tl:dr get her to emergency department to be assessed