Hehe, this brings back a memory not long ago forgotten.
So here I go with my speech, hope you don't mind me.
I always say good morning to someone and this someone always replies me with your reply haha
So I tell this someone, isn't it a good morning because you are talking to me? Xd it's the same with your mom. It's a good morning to her because she is seeing you. ;) so I guess if you tell her good morning it will make her happy knowing that you have a good morning because you are seeing her too.