Two Questions:
First, why doesn't she just give them the doll once she realizes that they are bad guys intent on finding it? I can understand why she doesn't when she thinks they're the police and it may implicate her husband - but at a certain point, she realizes that they are NOT police, NOT doing a murder investigation - and yet she risks all to avoid giving them the doll (which she proceeds to hide in the garbage can).
Second, why does she stop lighting the matches? Rout is covered in gasoline/ammonia and she'd been holding him at bay, making him tap that cane - then when the refrigerator door is open and there is light, she suddenly stops lighting the threatening matches - how come? What did the light have to do with it? Don't the matches pose just as great a danger to him as they did in the darkness?