9 month old cat is eating a lot more and is unusually active?

At the beginning of August I adopted a malnourished, stray female cat about 7 months old. She is now about 9 months old, was spayed September 1st, has had all her shots and does not have feline leukemia, and is a healthy (lean) weight of about 7.5 pounds (she has a small frame). I have noticed in the last week or so that she is always meowing for more food. This is not normal for her. She used to leave some food in her bowl and was somewhat picky, but now she gobbles down every last bite. She cries for more food several hours later. I can't tell if she is drinking more water than usual and I haven't noticed yet that she is peeing more than usual, but I am watching for that because they could be signs of diabetes or hyperthyroidism (but that would be extremely rare in such a young cat as Oreo). However, I really can't see how she could have diabetes because that usually is accompanied by a decrease in energy, and another thing I have noticed about Oreo is that she is way more hyper and active than usual. She is a very playful cat, but this week she wants to play ALL the time. She sprints after a ribbon up and down the stairs for 20 minutes straight, takes a 5 minute break, then she's ready to play some more. She is somewhat less snuggly this week. Instead of hopping in my lap in the morning she wants to play wrestle and be rowdy -- this despite the fact that we exercise her a ton everyday and we even let her play outside for several hours in the evenings (when we are there to check on her). So what do you all think? Maybe she is just having a growth spurt and needs lots of calories? Perhaps her activity level can be explained by the fact that she is finally fully nourished and at a healthy weight after 2 months of eating high quality food and so she is just a happy, rascally kitty? I have never cared for a kitten before, so I do not know if they have growth spurts like this, especially at 9 months (but I suppose her growth may have been stunted as a small kitten due to malnourishment and so she is getting a late growth spurt?).