That’s a HORRIBLE idea on many levels. First, because you attract attention to the fact you have a house servant. (Not seen as a positive in the US. Opens the possibility you’re a spoiled kid who can’t do his/her own laundry and is used to having others picking after himself/herself.) Second, because HOW IN THE WORLD can you imagine your house helper has nothing else to do than to spend time speaking about you for American colleges her own kids have no shot at - will you do her housework while she prepares what she will say? Will your parents give her three days off to do it? Third, this is a letter without value, because obviously you’d translate it for her, so you’d know what she’d write, and since you’re her boss’s kid, she is obligated to say nice things, or even fabricate them. It’s a horrible thing to do to her.
Honestly, it pushes the concept of “entitlement” to a new level and I can"t imagine any officer reacting positively to it.
In any case, having three letters is absolutely fine.