Now, obviously this was just a silly game we were playing. She explained to Mum that it was a pretend wishing circle, not a real one. But later it struck me that this is exactly what having the power to change history would be like in a self-consistent universe. All of our memories would be consistent with the new history, of course, and we wouldn't really believe that we had the power to change history (that would be logically impossible) but still we would try and who knows, maybe we succeeded.
I have no idea what the universe was like before those wishes. I strongly believe that it is better now that a) I have a daughter, and b) she has sweets on top of the fridge.
More: Novikov self-consistency principle