Well, the slogans used by proponents of more restrictive copyright policies aren't themselves the basis of the law, and even if many people seem to be amenable to the notion of ideas as property, actual copyright and patent law still don't work that way.

I don't agree that ownership of ideas is something built into human nature; physical property as been with us from time immemorial, but the modern notion of copyright is only a scant few centuries old, having been established by positive law and not recognized under common law. The notion of "intellectual property" is even newer.

Perhaps your daughter is being influenced by the current milieu, and not expressing an intrinsic equivocation between copying and theft that originated within her own mind.