How can one deal with a mother who asks too many questions and interrupts conversations, while avoiding disobedience to parents?

What you describe about your mother may be found in some people, either by nature or due to a mental deficiency. The duty of others towards this type of person is to endure and be patient, while trying to avoid confrontation and to shun matters that lead to arguments. Good character, patience, and overlooking people's faults are virtuous manners. How much more so if the one characterized by this is a parent? If your advice to your mother is without raising your voice, blaming, or saying anything that angers her, then there is nothing wrong with it. But if your interaction with her involves what we have mentioned, then that falls under the category of disobedience to parents.