No, that's exactly what I said, and said about two pages ago. She can apply but she doesn't have it now. If the UK revoked her citizenship today then she'd be stateless as she hasn't applied and been granted it from Bangladesh. Do you think they don't need any paperwork? What if someone doesn't want Bangladeshi citizenship, do you think it's forced upon them?
But again, this is about a specific case. The general picture is what people in this thread are worried about, not just her.
EDIT: Let me put that another way. Anyone who has the username igovernor is automatically entitled to ten quid from me. Is that ten quid in your pocket now?