I think my mum has Schizophrenia

My mum has been showing signs of schizophrenia for over a year, she was taken off her medication and a year later she started saying people were going to sue her and even went to police station!! She's been like this for over a year and has days where she gets really angry and blames me for stuff I haven't done and thinks people who I haven't even heard of are going to sue her, she says these things to my gran who has admitted she has been like this in the past, she has started getting worse and I don't know what to do as she has an injection every fortnight and it isn't working but I don't want her to hate me if I tell someone and she ends up in a institute.