Dear Tom;
Some of the mannerisim you depict of your sister are not far from a person with "altered perception" of themselves, the immediate environment of person, space and objects. You are right that she is sometimes in a world of her own this is due to her altered perceptions that guide her thinking pattern and hence thou outcome behaviours is a challenge to her and people around her like you.
As you might (Iam assuming)have discovered people with a scizopheria illness tend to have an altered view of things. Some do feel comfertable others do agonise with the experiences.
NB--The challenge is ussaully on the immediate persons (like you) who struggle to understand and make sense of what is going on for their loved ones. This conflict unfortunately affects our actions and sometimes judgement towards these people with an illness.
I would suggest that she sees a psychiatrist to assess changes in her psychotic symptoms because they do change when there are changes (cahllenges) like in their social/biological...lives.
If she is already on treatment this mmight need reviewing through increase in dose or complete change of medication.
I would also suggest that you find if there is a local carer's /relatives group for people living with schizophrenia as this has proved to a very good reosurce. The objective is to get to know more in order to be more able to support and understand your sister. Ask her is she wouldn't mind you escorting her to her Doctor.
Best of Luck
