I agree, it's normal, they hear my kids calling me mom so they call me it too. I think that they think it's my name, My at one point they were all calling me 'mama', slowly as time has gone on, they all call me by my name, but one, who is actually learning to say my name. I just kept referring to myself by my name, and eventually go it. When they were old enough to understand, i explained that mommy and daddy are their parents and i am their daycare provider and I go by my own name.