Hi Ryan, I'm a native Japanese, but not a teacher. Reading only the above conversation, I interpret the second sentence: ごめん、昨日は夜 [遅くて = 遅い時刻まで何か (仕事/勉強/遊び/...) をしていたので or 寝た時刻が遅かったので] 、 今朝も [早かった = 早い時刻から何かをしていた or 起きた時刻が早かった] から 昼はずっと寝てた。 "夜遅い" means that a person is active in the late night (e.g. midnight), and "朝早い" measn that a person is active in the early morning, without saying what he/she actually does. Because one has to get up before he/she does something, we don't think we have to say "起きる" to express "朝早い". Hope this helps. Hideki