Yeah there's some thing, I forget what it's called, where real life in incorporated in your dream. Maybe the son was going into her room to tell her about an alien he imagined? Because when I was younger, I tried waking my mother but couldn't, so finally when she did wake up she asked "Were you shaking my arm to wake me up?" which I was. She said that she was having some weird dentist dream, and one of the nurses shook her arm in her dream while I was shaking her arm in real life. If that makes sense.
I once put on alarm but I was so tried that when it went off I still slept but the sound of the alarm was in the background of my dream for about a minute or two
Merry Christmas!