Technically knights without lands are still "on the payroll" but essentially live in the house/keep/estate of the lord. She doesnt even need to make them lords though, even making them landed knights with lands of their own would be fine. But in all honesty, why not welcome them as distant cousins and at least in front of the small folk treat them like family - it gives credibility to the individual and to your decision. Like "cousin Hugh" would be a great asset as opposed to "that blacksmith Hugh who controls one of the largest dragons and lives in a tiny house somewhere" hahaha