MIL and baby shower.

Na
 Long story short. 
MIL begged us to let the baby shower be her gift after we told her three times we wanted to pay for it so that we could do everything our way and not make anyone feel bad. (It was already 80% planned and paid for anyway)
She begged and said she wouldn't interfere in any decisions, she just wanted to pay for it. 
It started off with a few guests that I really do not care for, but didn't mind adding. 
Upon seeing the final guest list, which included friends and family members of mine that she does not like. She comes to us at the last possible minute, with a new string of 10 guests including people she knows we cannot stand, and demands that we change the invitations (which are stamped, sealed, and ready for the post office) to include her phone number as RSVP so she can finalize and VETO guests!!! 
Is she crazy or am I?! Attempting to resolve I keep saying she just doesn't have to give us a penny for it, but we aren't making the new changes, and she's about to call her entire family and tell them not to come at all. 
Please HELP. My husbands head is spinning because she keeps talking to me through him and she's not listening to anything he says.