M.L.
Are these people personal friends as well as employees? That may make a difference. Gifts to friends are more personal.
If, however, you consider them employees, you could give them money - that's the standard gift for this sort of relationship. Or you could give a gift card for a store you know your sitter likes. I would also give the daughter a gift card, too, for a store SHE likes - which is probably different than her mother's preference, don't you think? ;^)