It's just usually a quirk of genetics...a lot of us have come out with a mutant here or there, odd leaf placement, missing parts, additional pieces or leaf tips....
I feel like she'll grow out the same nonetheless, just let her do her thing, shell let you know if she needs special treatment along the way. So far though she seems happy and healthy.
Im glad you mentioned taking it down to 18, i always think plants enjoy a little rest, maybe it'll help reduce extra stress on her. Happy growing, look forward to seeing the mutant thrive.✌️