Thanks, everyone. It does look as though she was plaiting straw hats of some kind ...but the more I look at it, the more it looks to me as though the first letter of the Sultana??? word could be P rather than S (as, indeed, Anne suggested). Puttana is of course Italian for prostitute. Surely there could not have been a hat in fashion in the 1870s called a Puttana Hat - has anyone heard of such a thing?
Anna