Reason behind unresponsive episode?

My mother has been on antipsychotics and antidepressants for more than 10 years now since she was diagnosed with schizophrenia, however, she used to remain drowsy and sedated for couple of days on and off with these medications, but few days ago she had an unresponsive episode with a lot of saliva coming out of her mouth, she was admitted in emergency after that episode and her basic blood tests came ok, later her sugar was checked and it was 224, after 4 units insulin, it came down to 222, they gave another 2 units and it came down to 169. My mother remained on and off drowsy,forgetful and confused+++. Her GCS score might be 14-15 when she's able to answer any questions. She was giving wrong answers to most of the questions. But they discharged her even if she was drowsy, confused and forgetful. She is still confused and doesn't remember things or events happening around her when we talk to her and ask her to recall things. Pls advise how to check if she's stable and safe to be home.