Lumen, the settler is a very common word, Britain used to have many of them. Five letters are swapped for...
10 A. Again five letters are removed. The answer isn't a word I'd have immediately thought of for 'swordsmen', but it all works. You need the usual stuff for 'small', usual stuff for 'girl', and reasonably usual stuff for 'lady's'.
PS For some of the thematic answers, I just stared at my keyboard - a couple of times things jumped out at me. That's what happened with 10 A.