In TAC, Holly is badly injured and passes out in order to heal. When she is forcibly awakened by Foaly, she has not yet fully healed. Magic sparks still play across her vision.
Except they're not blue. They're amber. Wacky.
Holly dismisses it as age, but we know there is little to this theory as in TOD Root, who is much older than Holly, trys to heal himself after his ribs are broken. The sparks, described in the book, are blue. So the cause is not age.
After a long time of talking this over I have come to a conclusion.
Holly is losing her magic!

Maybe it is the human eye that she has gained- a plot gun that has taken a while to go off. Maybe it is the amount of healings she has to perform. I may be utterly wrong. But I'm pretty damn sure I'm right.
What does this mean? Will she be exiled, and forced to leave LEPrecon? Will she be able to live with Artemis, as this could hint at their species coming much closer together? Only time will tell. But I thought it was a pretty neat discussion point.
PS. Why did nobody look at "Atlantis code- decoded"? My first post and nobody looked. Trauma clinics aren't cheap you know.