Margaret and Borachio, are you completely sure?

In the plot Don John and borachio, do a mischievous plan in
order to deceive claudio and the prince that margaret
was unfaithful. The plan is that boraccio will hook up
with margaret at heros room so that claudio witness
it at the window, believing it is hero and borachio.
But, how can we be completely sure, what gives us the
certainty that it wasnt margaret and it was actually hero
that hooked up with boraccio. Shakespeare let us witness
the scene from the outside POV, he never gives us a
Omniscent POV on all of his universe. Have you ever heard
about those stories that actually happen that the lady of
the house has a sexual encounter with a servant?
I´m still not sure how was exactly the boraccio-Don John
relationship, was don john the master and boraccio the servant?
What about margaret and hero? Margaret was supposed to be
her "waiting lady" (im not sure what that is, explain please).
Why didnt hero appeal herself against the accusations at her wedding?
Okay, maybe because she was a naive youth and dependend upon others.
But if she had a close relationship with margaret, why didnt margaret
tell her anything. Okay, Lets say it was margaret whom actually hooked up
with boraccio (as we all thing it is) lets say she didnt tell her anything because margaret
is evidently sexually experienced and hero is not. So in that naivete that
hero has, she just got in the flow with boraccio and had sex with him without knowing
it was socially wrong. Just like a kid is sexually abused by an adult and the kid thinks
is just a normal thing people do, until he grows up and realizes that the experience
was not morally right. Things like that happen all the time. I mean, do you
really think Leonato never had or at least attempted to "woo" (I mean iniciate sexual
intercourse) with any of his servants? Think about it.