Marry the female courtier to your heir (or yourself), then press her claim, then form an alliance with her and make sure to join all of her defensive wars so that she doesn't lose the land. Eventually the male child you have with her will inherit her land, and yours as well (or your heir will have a child with her and your grandson will inherit).
However, whenever I do this, she always dies before I do which means I end up with a 7 year old son I have almost no control over, so as soon as he comes of age as the ruler of his new province he's doing all kinds of stupid things, like picking stewardship as his focus and getting stressed and depressed at the age of 17, or leading armies by himself and becoming a one-legged one-eyed mess. Or converts to Lollardism. All maner of ridiculousness.
Generally I absolute hate my heir being landed and avoid it as much as possible unless role playing.
