Baby boy names

Ok mom's my fiance and I have been struggling on finding the perfect name for our baby boy.. his mom has been pissing me off about it.. she's constantly saying oh u guys have to understand that you wouldn't want to get picked on about ur name and what not then she brings up a name that we named our son that was born sleeping and she's like u should name ur son that.. I loved that name ... then when we say we are not naming him that bc of it being our first son name she starts running her mouth saying that he shouldn't have a name bc I didn't give birth to him and I don't have a birth certificate for him... what do I do.. she's not making any of this easy