Found this on Genuki
Marriage Settlements
Until the Married Women's' Property Act of 1882, the property of a single woman passed automatically into her husband's hands when she got married. To protect their property and, perhaps, to secure some independence, women often transferred their property to Trustees, who would then legally own it, but use it to the benefit of the wife (and her children) rather than her husband. These legal documents are normally refered to as "Marriage Settlements."
Denny Lowe of Canada adds this note for researchers: Colin R Chapman, in "Marriage Laws, Rites, Records & Customs" states (on page 65) 'Marriage settlements in England, Wales and Scotland were personal documents and so, only by chance, are likely to have found their way into county or similar record offices.