BB clothes should always be washed by hand of course.
when the maid just arrived, better wash separately - if no problem of hygiene concern, i'll let her wash our clothes together.
i never let my helper use the washing machine for her own stuff. i asked her to wash baby's clothes by hand and then put them into the machine for spinning becoz it's a waste of energy and water to use the machine to wash the bb's clothes which are only a few pieces each day.