Yes sukhdeep he is manglik and it would be better while searching a aliance for him, the girl should also be a manglish to counterfit the dosh. Along with mangal, shani and ketu also poking there nose to delay his marriage. Give me some time will advice you the right remedy as i know few things your brother can’t be willing to do.
Don’t worry she will catchup slowly, her inteligency will be towards outside the study world. Just do balle balle……