First I will reiterate what Gilmore said about they are the parent and you are the child. This is not your fault or anything that you are supposed to handle. They should be able to resolve any issue they have with each other.

To provide a possible explanation, perhaps your mother sees the men in her life suddenly changing and trying new things and being passionate about them and this makes her feel uncomfortable or unnecessary. I can see how a mother and wife might find this unseteling especially if it's something she does not appreciate or understand.