Maybe your husband does not know how to respond to her tantrum, or maybe he is afraid that if he gets involved, he might not be on the same page with you(It happened to us). Talk to him about how he feels when your daughter throwing tantrum and ask him what his approach is if he is the one to discipline her. Regarding your daughter's tantrum, it might be something bothers her making her behave that way. Welcome her to talk about the problem in detail and do not judge her feeling, giving her a ear and show your understanding. Ask her about possible solutions she can come up with the conflict. It will take time. Good luck!