issues w the mother in law

so I'm 6 weeks Pregnant and me and my husband always talked about doing the gender reveal party, which my mother in law hates because she wants to know the sex of the baby before everyone. so she went to my best friend who will do the reveal and told her she will tell her the sex , that she will keep calling her and go to her house till she tells her. and also told her to throw her a grandmother shower ..... this is very upsetting to me, my in law has always made a way to make everything about her but I didn't think she would go to this point. I'm not sure what to do... any ideas? anyone has this issues too?