Ah, couldn't see that in the pic - sorry. I did come across this elsewhere though and the plant started growing normally once it put out its second or third set of leaves. I wouldn't worry as long as she's healthy. That's the thing about us girls. Take good care of us and you'll get the rewards you're looking for.
Happens ...... heard it happens a bit more often in kush / og strains . Had plants start 3 finger , go 5 then 7 / 9 fingers .
Never had a 15 finger one but heard about them .