There may be a bad scene at my wedding with guests

FMIL has a friend named B. B is crazy - those words come from FMIL, not me. B has a daughter, J. J and B had a HUGE falling out and J has no interest in speaking with her mother.

When we were making the guest list, FFIL told FMIL to invite only one of them, becuase they will likely cause a scene. She blew that off and said they wouldn't. FFIL said 'well do you really want to use the wedding to test that out?'

So FMIL told me she only invited J. However, an RSVP came back from B, obviously sent without me being told about it. Fine, no problem. B's RSVP said 'Please seat me with my daughter, J.'

Yesterday J's RSVP came back and said 'please make sure I am not seated with my mother.'

Now I know this is FMIL's problem because she has to do the seating for them. But, I can just picture B causing a scene if she's not seated with her daughter. And if she tries to sit with her daughter anyway, her daughter will scream.

Ah!!!!