A light research tells me that Sherlock Holmes in the original books gets engaged to Charles Augustus Magnussen’s housemaid, Agatha, who was like Janine in the BBC version. And she also meets with the same fate as Janine.
Now, in Dracula, the name of the nun who is standing against Count Dracula is called Agatha. She says she has a detective acquaintance in London. For sure she is not the same ‘housemaid’, but a nun. But maybe her character in the show has been inspired by the housemaid from the Sherlock books.
This could be true because MOFTISS.