Solving same Gotra issue with changing religion to Christianity ?

Iam a hindu boy of 25yrs of age,iam in a deep love with my gf for past 7 yrs .i want to get married to her as she's my life..iam emotionally to much attached to her as she was with me in my all up n downs of my life.she holded me firmly when i lost my father at age of 20.i really love her alot n want to marry her but the problem is that we both belong to brahmin family and our gotra is same.however our family doesn't have any relationship btwn them.i knw will marry eachothr at any cost,but i dont want to hurt my mother.we dont believe in this shit but society does , so to avoid hurting our parents we have decided to convert my gf into christian as this shit will b removed on paper as the religion is once changed.then there will b no such talk in society as the religion is changed n then no such nonsense prevails.my gf is willing to do it as ee believe in one god.ultimately she will b married to me n we can enjoy both the cultures..she can keep the christanity as her religion even aftr she is married to me..since we find no other option pls suggest us is it correct..if so then pls suggest the process of conversion..ultimately we have one life and we can't waste it like dat..n god is one.