The actress is reportedly unaware that the former Celebrity Big Brother winner is now engaged to millionaire boyfriend Raj Kundra.
A source told Bollywood Hungama: "There's a provision for a housemate to be brought out in a case of an extreme emergency.
"It happened with Jade Goody last year. But does a sister's unscheduled wedding qualify as a family crisis?
"We're now wondering if the same rule as Jade can be applied to Shamita's case."
The source also revealed that Shilpa will be meeting with the producers of Bigg Boss to devise an eviction strategy to get her sister out in time for the wedding.
It is expected that host Amitabh Bachchan will break the news of the marriage to the contestants.