Re: A hindu-muslim wedding!!!
Hmm....very interesting subject.
Has several layers....like an onion.....but if I were to ignore all the other obvious issues with this situation then I would have to say that you incorporate the jai-mala and the mangal sutra traditions as these are somewhat already performed in many Muslim ceremonies.
We may not consider them a part of the actual ceremony and do them as a tradition outside of the nikah but we do exchange garlands and we do offer the mangal sutra more commonly known in our circles as kaali poth. (See tradition in Hyderabadi culture.)
If this was happening in my family I would have some serious issues with any sort of pooja-paat and phairay as my understanding is that these are religious in connotation. I simply would not allow that.
It is a very difficult situation when a child decides to leave the faith that they were born into to marry a Muslim, particularly if they are not from what we consider "people of the book" as their ceremonies are in direct contradiction to Islam. I feel for her parents and I wish that when people take such steps they would be so steadfast in their decision to convert that they make it clear to their parents that no such practices will be tolerated. But that would be utopia, wouldn't it?
The unfortunate side of the matter is that many such conversions are not entered into for the love of Islam but as a matter of convenience so that they are able to have a nikah performed; a sort of formality that is viewed more as a necessary evil. (I am not suggesting that this is the case here so please don't be offended.)