IGI has a William Starkey marrying Margaret Clark 27 May 1854 at Kirk German. If they are the parents of Elizabeth born 1859, do you know of a reason why the name Clarke would be included on her gravestone? Do you think it's a reference to her mother's maiden name for some reason, or are you aware of her marrying a Clarke after her husband John Collister died in 1891? Sorry, that seems like a lot of questions - she may not actually be at the centre of your researches, but I'm curious...