What does it mean in the context of "her mind has just turned to mush."?
From the desperate housewives

Mrs Huber:
"When it comes to discipline, sometimes you must be creative. My mother knew that.
Smart lady. Of course, she's in a home now. And her mind has just turned to mush."

Please let me know what the real meaning of
"her mind has just turned to mush..."

Question

What does it mean in the context of "her mind has just turned to mush."?
From the desperate housewives

Mrs Huber: 
"When it comes to discipline, sometimes you must be creative. My mother knew that. 
Smart lady. Of course, she's in a home now. And her mind has just turned to mush."

Please let me know what the real meaning of 
"her mind has just turned to mush..."

Answer

It means she got old and senile, her mind does not work as well as it did when she was younger.