It really depends on your overall layout, which we don't know, so we won't be able to help you in detail.
If you're Editor is using events to determine the mouse position, then you'll have to think about how to dispatch it to all the other components. I'd immediately think of a message bus design (see
Tank's article on this), but it might as well be overkill.
On the other side you can simply use the
sf::Mouse class. Since it provides static functions, you can call them where ever they are needed.
Again it depends on the overall design and in many cases you should with the solution you can think of at this point and only refactor it, if you run into a better solution or you get some problems with the current design.