It's intuitive to say she sould be on the side the smaller mass is placed. How far from the balance point?
Let's call x that distance. and assume that the contraption is "oriented" so that being on the side with tiny (and teeny) gives you a positive distance from the balance point, and negative on the other side.
At equilibrium, the sum of all momentums (momenta?) will be zero:
In layman's term, she has to be halfway between the balance point and Tiny.
We are assuming that the floor (field) is completely horizontal since there's no information about that in the statement. We are going to use the following formula: