Jealousy?

Okay, so my child is starting preschool on Monday and I am going to be a sobbing mascara-dripping mess. Thankfully a very good friend has cleared her schedule that day to help me get through this new transition. I was telling my MNL about it and how nice it is to have such a caring friend and her response in a tone that implied she had hurt feelings was, "Oh, well I was planning on taking you shopping and spending the day with you but that is great. I'm glad you will be doing something to take your mind of of it". Now, that is the FIRST time I'd ever heard anything about spending that day with me or any sort of a shopping trip. So, is she jealous that I am going with a friend? Why the sad eyes and look of hurt? It is so strange and the unpredictable responses give me whiplash!