What do you mean with 'using Earheart would be confusing'? To clarify any confusion is precisely the point of a single dab page, to which both spellings would redirect to. Thinking of all the readers who put 'Earhart' or 'Earheart' in the search engine, I'd say that possibly a significant number of them have made a spelling mistake and as a result are taken to the wrong article (e.g. they put 'Earheart' while looking for the aviatrix). Also, there are two ships named Amelia Earhart, so both should be mentioned in the hatnote, as it currently stands, which would make the hatnote cumbersome; better to move everything to a dab page.