Wedding Announcement

My second daughter is getting married. We are having issues with the announcement. When the 1st daughter got married we put the grooms parents on the announcement because they said they were going to help with the wedding....well not one dime was given towards the entire wedding.
This time around our new son in law is an only child (groom) with a single mom (makes good money) The kids have asked her what she could help with several times with NO answer. Mom went on at least 3 crusies last year, she spoils herself and has not changed her lifestyle one bit to help these kids. She is going hours away to buy a very, very expensive dress for the wedding, yet she does nothing to help the kdis. We on the other hand have taken on extra jobs as well as not going on a vacation and having a very small Christmas so we could help more. Can we opt for the tradiational wedding annoucement with just the brides parents on it? Is that rude?
Feeling very frustrated, the groom is very close to us and we love him like our own. He feels his mom is a selfish person, they are sick when they have to ask her for anything....I told them not to ask anymore, we would find a way to work it all out....help!!