Aww Amy she is adorable! I could see how she could steal your heart so quickly! I'm glad to hear it's just a growth spurt and not losing weight. I would still look into the other food though just in case she starts losing weight in the summer. You never know when you will need it, so if you have a good handle on whats what you will be good to go if needed!
I'm also late for my growth spurt.. darn it.
TM Tardy's Chick "Hunter" - 13 yo Paint
Remmy - 18 yo Morgan/QH cross
Gunner 3/31/11, Heidi 7/2009 Miniature Sicilian donkey