Correct footnote:

Your footnote above should look like this:

Jennie Elizabeth Batchelor, 'Dress, Distress and Desire: Clothing and Sentimental Literature' (unpublished PhD thesis, Queen Mary, University of London, 2002), p. 170.

Comment:

The majority of theses or dissertations you encounter should have a title-page which states all the information you need. For others, you may find additional information through electronic databases (such as the British Library's EThOS).

Important Note: Dr Batchelor's thesis actually has been revised into a book, called Dress, Distress and Desire: Clothing and the Female Body in Eighteenth-Century Literature. As such, good scholarly practice dictates that you should no longer cite this dissertation, but should cite the book (which is more widely available) instead.