Is a mother's saying to her son's father, "He babbles in his speech"—intending that he sometimes speaks foolishly—considered backbiting?

Forbidden backbiting is to mention a Muslim with something he dislikes in his absence, whether it is concerning his body, his religion, his worldly affairs, himself, his creation, his character, his property, his child, or anything else related to him, by word, writing, or sign. And "describing one's son as rambling in his speech" is a form of forbidden backbiting. Backbiting may be permissible in certain situations for a valid Sharia purpose, such as seeking redress, or seeking help to change an evil.