We do the same thing with my 7yo step daughter sweetie, if she is yelling out before 7am (which we strongly discourage because Dyllan is opposite) we tell her that she can do something quietly but we will come and get her at 7am....I think it's reasonable. Dyllan HAS to wait for me to come and get him (as he is still in his cot) many mornings as I am feeding Caleigh, he doesn't mind and I don't think it's bad for him, gives him time to wake up and be cheerful
xx hugs to you lovely!!