A 7lb loss for anyone of normal size would be significant, but it's nothing for someone of AL's size. Try weighing yourself several different times on the same day. You'd be amazed by how much it can fluctuate based on the time of day, when you last ate, what you're wearing, how hydrated you are, etc. You can weigh in first thing in the morning at 150, for example, and then be 155 right after lunch. Obviously, you didn't actually gain 5lbs. Water retention and all that food sitting in your stomach counts for a lot. That's why, to measure weight loss the most accurately, you're supposed to weigh yourself at the same time of day wearing more or less the same clothing.
Long tangent, but it brings me to my point: 7lbs is nothing for someone who weighs 550+. It's a matter of weighing yourself after dinner one day and when you first wake up the next time. I really, sincerely doubt that AL has been keeping any kind of consistency in her weigh ins for us to be able to trust these metrics.