What do you think Daring Do's backstory is?

I'm guessing, since shes drawn from it, is that it's kind of Indiana Jones esque in nature.

Maybe she found some artifact or something similar and wanted to sell/offer it to a Museum, but of course, money grabbing sharks and all that.

And she later on became a writer under her alias to keep some of her more annoying, if not socially standable enemies at bay. Or to just sell off her adventures.