Mother In Law To Be Has A Guest List of 50 To Our Wedding – Leo and Rebecca Buzz Question

Leo and Rebecca Buzz Question - Hey guys, in the process of putting together our wedding. We do have a budget and things were going pretty good until this past weekend. We agreed on the guest list. You see, I have a guest list of 75 my wife has a guest list of 75 and this weekend my wife notified me that HER MOM has a guest list of 50! I ain't gonna lie, I didn't think my soon to be mother in law was even going to put a list together. I figured my fiancee's list was part of her moms. How do I handle this without causing some ish??? Help!