Sorry for the incredibly late answer, I forgot about this until quite absurdly, the Nick Jonas-Priyanka Chopra engagement pics reminded me, lol.
As it always comes down to, there’s a difference between what Rana and Kate as people would do and what Corrie would show. Corrie just doesn’t have the budget or time to show anything very elaborate and anything like what a typical desi wedding would be. And it would be the desi part that’s important, not just Muslim. Weddings are different across the Muslim world but desis like a specific kind of thing. That’s relevant because the role of Islam in Rana’s life is hard to pin down, she’s never been very religious and right now it’s been causing a lot of trouble for her, but she’s still very much Pakistani. And you kind of need a large number of family and friends for those ceremonies to work, they’re actually heavily involved, and at the moment they’re estranged.
In the ideal scenario if Rana’s mom did accept her and possibly even the rest of her family did, and Corrie bothered to show all this, there’d be several ceremonies, and Rana and Kate could be involved in both. As much as Rana doesn’t care about religion, I don’t believe Kate cares either, so she’d probably be willing to go along with what Rana wanted, especially if Rana tried to make it more desi and Muslim to try to appeal to her mom. There are so many ceremonies, there wouldn’t really be an issue including one more of the kind the Connor ladies have (without the drama).
Aw, now that I think about it, it’d really all be very beautiful and fun, especially if Rana’s mom ponied up some serious cash to make up for being such a monster.