Well, it could be a mutant trait or possibly stress... I say, as long as she keeps looking as healthy as she does, you shouldn't worry. Let me know if you see any other changes in the plant. She may take longer than the average plant to flower, so this one might test your patience. ;-)
Do you have pic of it? I am soo not good with lighting questions... Sorry, but I can probably tell by the way the plant looks as to what's going on. ;-)