Below are some examples of how mom could approach this:
Mom could say “Please join me for breakfast just as soon as you are dressed. Breakfast will be served until 7:30.” If he gets dressed quickly, he’ll have time for breakfast. However, if he’s slow then he’s likely to miss the 7:30 time frame and also breakfast. Mom can definitely expect an uproar if he misses breakfast. She might be comforted in knowing that he will not starve and he will probably change his behavior so as not to miss breakfast in the future.
Mom could also give him a choice, “You can either get dressed at home by 7:30 or we can take your clothes in a bag and you can get dressed at preschool.” Again mom can expect some serious protesting if he ends up having to get dressed at preschool. However, she will probably not have to take his clothes in a bag very often (unless he’s an unusual child who likes to get dressed at school!).
Another approach mom could take is to reward him for getting dressed on time, “If you’re dressed by 7:10, I’ll be happy to read you a story while you eat breakfast.” Mom should also make it clear that breakfast is only served until 7:30 so it is possible for him to both miss the story and breakfast.
Mom needs to select an approach she is comfortable with since it is critical for her to follow through even though it may be very difficult. If she follows through with what she promised, her son will soon learn she means what she says and will adjust his behavior accordingly. Most parents are pleasantly surprised by how quickly their children’s behavior improves once they experience consequences other than their parent’s nagging, yelling or lecturing!