Serequel is not working. She is just as miserable as ever. What else is there?

You said she is in last stage of Parkinson’s disease?
This is something neurologist would have to asses and make changes.

https://www.agingcare.com/questions/is-there-anything-besides-or-in-addition-to-sinemet-seroquel-and-trazodone-for-my-mom-in-the-last-st-477418.htm?orderby=recent

Above is a link to your other question in late September on the same subject, with all the comments you received.

What does your mom's doctor have to say about Seroquel not working for your mom's Parkinson's Disease? Is she taking it to treat psychosis? You give no details here at all.

According to Google:
Which antipsychotic is best for Parkinson's disease?
Clozaril (clozapine), the only drug known to be both effective and well-tolerated for treating psychosis in Parkinson's patients, is prescribed to less than 2% of those with the disease.

In certain cases, there are no pills that will make an elder less 'miserable' if they're chronically complaining. What constitutes 'miserable' for your mom? And again, what does her doctor have to say about the situation?

what is she taking seroquel for? no way to suggest alternate medication possibilities without knowing condition.