I dunno. I would think Magik would be okay with it because it's coming from the one person who basically loves her unconditionally. It doesn't matter how bad it gets or what she does, he'll always have her back. It isn't said to *ignore* or *downplay* all the hardships and trauma she's been through--it's done to reinforce the fact that she'll always be his little sister (snowflake) who he loves.
Kind'a why I think it was completely out of character of her. She would never want to do that to anyone.. much less her brother.