I love a girl of opp. religion 2 me even she loves me... my parents r ready she dnt hav father so her mum is..

i luv a girl who is in opp. religion 2 mine. i am a sikh(19yrs) & she is a hindu(20yrs) by religion & age. she also loves me.. The prob. is dat my parents r ready as i am a single child of dem but she dnt hav father so her family inc. 2 elder sis who hav choosed deir own life partner but still unmarried & 1 mother but none of them r ready 2 except me as son in law of dat family... dey said 2 her(my love) dat as an human being dey r very happy 2 make me a son in law but the prob. is dat my religion is different so not possible at all... i really dnt knw wat 2 do neither she knws.. v cant marry by running frm home cos my parents r ready so hw cud i break deir dreams & she thinks if she wil tak such a step den her mum wil die which obviously she cnt see neither i can.. deir is a big issue 4 us 2 take ne step which can make us 2gether 4 ever so plz help...