Flowering NL's have weird shaped leaves

I've got this Nirvana NL that has been flowering for weeks and the buds are massive. The pistols are still almost all white and it keeps pumping out the flowers, but the top bud has started producing round smooth leaves. I've kept no records of this grow so I don't know exactly how long it's been flowering but it's pretty damn close to done. I've already cut down her sister because her trichs were a bit cloudy with the odd amber here and there.

I can't get a picture of it now, but those leaves look almost like it might be in the process of regeneration even though the buds aren't ready. It's been under constant 12/12 from the start and there are no light leaks and if there were leaks I'd assume her sister would have shown at least some sign of the same weirdness. This is my first time growing this strain and these leaves don't look like anything like any pictures of NL buds I've found online.

Weird,post a pic when you can

Well, that plant with the weird leaves kept on growing and the main cola got so fat that a nasty pink mold started growing in the middle of it. It never looked like it was ready and those rounded leaves made it even more confusing. According to the color of the trichs it was just barely ready for cutting, but that mold forced me to harvest.