your question is somewhat difficult to understand, but i am answering in my way.
so your sister in law had made a
suicide attempt last year and reason behind this was wrong behavior of her husband. so she may have
depression but u can not name any psychiatric disorder, without knowing the symptomatology.
now, she is living with her husband but most of the time she has fear of any male person who will exploit her [sexually] and take her baby girl to sex trafficking. according to you this is present without any truth behind this. so this must be delusional fear, part of psychotic illness. it is not depression. she is denying to
consult a psychiatrist with a fear of possible exploitation from him also. this can be a long standing
schizophrenia, i can not stamp her as a person with schizophrenia but at least she has psychotic illness and has no insight.
so psychiatrist consultation is must. you can give her medications like antipsychotics but proper interview is must.
meds u can give her are:
tablet. TOLAZ MD [10 MG], half in the morning and one at night after dinner
if she denies for any meds, u can give these tabets in waer, juice or in food, because this is a mouthdissolving preparation of
olanzapine.
if she will take it regularly her symptoms will decrease in severity and then u can take her to a psychiatrist..do not give medications blindly for long duration without consulting expert.