W.Salam.. I am sorry i was away for the last one day.. U can write to me at [email protected]
, if i am not able to respond on time here or u have any other concerns.. Though i am not an expert but ill help u in whatever way i can..
Anyways now coming to ur point.. See ur case hasnot been finalized yet.. That means ur file is open , so whatver changes u have or u want to make u can surely write to them.. You can write to them stating that u wish to withdraw previous request due to the reaason's best known to u.. Explain them the reason's that what made u withdraw the request and now why do u want to include ur sister again.. I am not sure what their response is going to be but there is noo harm in trying..