I created a follower and placed her in Dragonsreach. Works great except that after marriage she does not grant the Lover's comfort. I read somewhere that this could be fixed by moving to the spouse's original house and sleep there. So I think maybe the problem is she has no assigned bed in Dragonsreach. I placed a bed near her location in Dragonsreach, but I don't know how to make it owned by her.

Double click on the bed in the render window and click on the "ownership" tab in the window that will open. After that select her name in the scroll down menu.