I don't know about the sleeping right in the middle of the act of playing but I know my MaeMae is a sleepyhead. She sleeps with me and my hubby is up at 7am and she won't even look up..... I sleep in and she just sleeps. Even when I get up late sometimes..... like 11am
she will still be in bed. I will go get ready in my bathroom and call for head and she won't even lift her head. When I get closer..... she'll roll on her back to show her belly. Like she doesn't want to get out of bed. She's the only one that does this and she is over 3 years old. I, personally, love this part about her. She will be aggressive and very active when we go down but she is a very calm dog when it's just her and me. When I take her out...... she'll stay in her bag for hours and not want to come out. I take her to movies and dinners and nobody even knows she is there. She is my angel. Your baby sounds more serious though.... I would just keep an eye on her.