Eager Teacher

My current dilemma...

I teach classes that sometimes reach numbers of 40 students. Because of the communication barrier and the number of students, the homeroom teachers are required to stay with the class while I teach English. This has been a huge blessing at times when the teachers manage well and at times a big burden. Many of these teachers are eager to learn English and become very active in my classes. One teacher in particular is very enthusiastic and perhaps feels a boost of confidence about her English abilities when compared to the students. She answers all my questions before the students even have a chance! Quite often I have a competition of some kind in class and she keeps giving away the answers. It's actually quite hilarious how genuine she is. Anything I ask the students to repeat she's right in there dominating the voices.
I've had to handle a situation like this before where I told an eager student to take a break and let someone else talk, but I'm not sure that the approach is going to be the same with a teacher.