When Jack first walks into the caravan and finds Sylvana's body, a pendant is visible on the chain around her neck. On the second time he goes to the body, the chain is around her neck, but the pendent is missing.
Jack finds that a rag has been stuffed into the chimney of the caravan's gas heater. It would have burned up from the heat of the exhaust gases, but when he pulls it out, it's not even singed.