Royall's page uses "The Baroness Ashton of Upholland" because it's about the Leader of the House of Lords and the peerage is used. Here, we are linking to the Commissioner for Trade which does not use the title and she is thusly "Catherine Ashton". This is akin to how Mandelson is only linked as "The Lord Mandelson" after he gained peerage, though in reverse. She hasn't lost it, but it isn't used when referring to her role in the EU, so we use her birth name. Should she re-enter British politics and become Secretary of State for Energy and Climate Change, the link would use her title in peerage.