Crazy Mother in Law!?

Me and My fiance have been together for 5 years now and have a beautiful 6 month old bbg!

We are in the middle of a family fued with his side of the family because of his mother. She just loved my baby and wanted to spoil her. It all started becuase my fiance went fishing with my father. and she got jealous. So they argued and stopped talking for 3 months . she never onced called to ask about her granddaughter or came to see her. neither did her mom or dad. her mom would come over every sunday after church to see my child but ever since we've got into she stopped coming. So me and his mom had a few choice words and i basically called her out on everything shes been saying. Now sshe called her son last night wanting to make ammends because they need "structure " in the family meanwhile shes the one who caused this and drug it out this long. and then she wants him to go to her house to talk but doesnt want me to be there, My  fiance stood up for me and told her if she cant talk to both of us at the same time then theres no talking. What do you think?