Communication principles are consistent whether on paper, on-screen or on-line. Kate is not a web-developer. She advisies on content and usability, working with developers to design user-interface graphics and functionality.
User interface (UI) and User experience (UX) design is the marriage of technology and good, old-fashioned communication principles. Kate understands the latter! She's described herself as a professional 'lowest common denominator', able to flag prescribed activities and assumed knowledge that may confuse the target user. Kate's skill is in challenging assumptions by asking the kind of questions (How do I know where to click? How would I know that it possible? Why is this useful to me?) that either the organisation, or the programmers/developers they've hired don't need to ask of themselves – and then recommending alternative approaches that will be universally comprehendable.