Milan has said that her contemporaries are science fiction, they just aren't being particularly noticeable about it yet. She didn't say when, but given that there is a behemoth of a book about Adam that she is writing in between and around all the others, and given the nature of his love interest, I think the science fiction aspects are going to become pretty evident in a couple of books' time.

Her historicals are definitely and consciously veering into alternate history - once the chromosome gets discovered earlier and in England, that's going to change the pace of technological change. So while she does meddle with history, she is fully aware of the consequences of doing so...