I have my 3 mothers planning one shower, and it's starting to become a nightmare (mom, birth mom, mil). The 3 of them decided it was going to be Sunday, Jan. 20th, but when they got together to fill out the invites they put Saturday, Jan 22nd. The day they got together, each one said something that hurt the other one's feelings. One brought up global warming, which offended another mom. One brought up cloth diapering, which offended one of the moms. Then, days later when they realized they had put the wrong date down, one mom decided she would do all of the fixing. MIL called DH to complain that out of the 35 on the list, only 5 were representing his side of the family. Not my fault that they don't talk to DH's dad's side of the family or MIL's 2 sisters, and there was no one else to invite from that side of the family.
I only tell you my story because I don't want you to feel stressed out like I am because I'm helplessly stuck in the middle, hearing the bickering from all three of them.