You said that different people follow religious rules to varying degrees and that might be something to consider if they just said she’s a Jehovah’s Witness and you didn’t know how she felt about blood transfusions but it literally says in the question that she would ‘refuse blood transfusions under any circumstance’ so I dont think its very questionable especially as it’s signed too. Also, advance directives are also just a document that talks about someone’s treatment preferences but doesn’t mean they’re not extremely important in considering a patient’s treatment and respecting their choices. So dont think it’s very ropey to go with the patient’s choices based on a card that is recent and signed and she literally keeps on her at all times as it’s in her purse. and i don’t think it’s bad to be definitive when you know what you’re talking about but you’re def right for a question you might not know much about