Mom refusing to invite husband's family to shower

My mom and I have always had a rocky relationship. About two months ago she asked for my and my husband's lists of who to invite to the shower, as well as his moms. His mom was helping with it and his aunts were making all of the favors. Seemed great. Today she decided that she no longer wants men at the shower and because his friends are guys, she's just not inviting them. She also no longer wants his family invited. I just can't with this so unnecessary stress. It's a baby shower, why does it have to be like this?

It's a month away from the shower and I'm going to have to plan another shower. We already live out of state and are having one in our state as well. This is ridiculous. What would you do? I tried to just convince her to invite people. The list of our friends and his family is literally under 20 people.

Update: it's not at my moms house, she's having it at a hall with plated food, should I just invite them and if there's not enough food not worry about it? Should I just call to invite them, she won't send them invitations.