Tax Preparer - Cpa Nightmare

My tax prep CPA - EA is dragging out my 2017 Trust return. Although my appointment with her was a little late, Mar. 12, she has repeatedly said..."I'm working on it," and promised 3 weeks ago I'd have the return by the following week. She did file an extension on the return, but I am very hesitant to again contact her to ask what's up with the return. The last time I contacted her she got very offended at my "insolent" inquiry on the progress of the return, despite my careful tactfulness. This CPA not only did my deceased father's and mother's returns for decades, but she was a "family friend" and entertained my widower father often. There is the possibility she may be dragging out the return out of spite, or she may feel she can put my return at the "bottom of the pile" out of some imagined liberty. I really don't know, but I do know I have a Trust to administer, and she is holding things up. She is in her 70's (senile?).
Requesting input/advice on how to proceed, or just wait? I'm in a quandry.
Questions:
Does an extension give a Tax Prep person the perception they can sit on a return, even out to October?
The tax prep practice has a partner...should I contact them (knowing my inquiry will get back to my CPA)?
I have a Trust attorney...at what point should I contact him for assistance, if at all?
What would be a common waiting period for a return preparation after an extension has been filed?

Thank you for any help.

Tax Preparer - Cpa Nightmare