Yes. In “Ethics of Our Fathers” we are taught that a wise person does not interrupt a person who is speaking. (Ch. 5)
Does this mean your friend is not wise? Not necessarily. I will try to explain in brief.
Our Sages teach that one who interrupts another is called a “golem”*. The word “golem” literally means an unfinished object, such as a utensil which has been shaped but not polished. The translation for “golem” in association with a person therefore is “unrefined”.
The fact that she interrupts you is not an indication of her level of intelligence. Rather, it reflects on an aspect of her character that could use refining. As you write, she is a good friend and a wonderful person. And very possibly quite smart as well.
As to how to deal with her interruptions? One thing you might consider is to ignore them and be happy you have such a good friend. Having a good friend is a very important thing and often rare to find.
Alternatively, you may choose to speak to her about the interruptions —for both of your sakes. If you do, I am certain you will know how to go about it with tact and love since she is such a dear friend and you don’t want to take any risk of losing her.
*Please note that the use of the word “golem” does not refer to the alleged artificial beings created via Kabbalistic means who were not-fully-functional.
