Just remind her before you sit down to the meal to take small bites and always chew with her mouth.
Now mom, you also need to remember not to ask her a question when she just takes a bite..
Talk about how if she does have food in her mouth and she is asked a question to look at the person, point a finger like "1 moment" and then finish her bite and THEN answer. Or she may hold a napkin in front of her mouth and say, just a moment please.
Our daughter used to ask "why do you always ask me a question when I have food in my mouth?".. Yes, she was 3 at the time. I apologized and told her I was sorry and then we discussed good ways for her to let me know her mouth was full.
Practice this your self when you all are eating. Have your husband also show how to do this.