Some would say she can do whatever a 3tomoe can with just 1tomoe!.. I don't think she unlock the second tomoe so why or how she got 3 when they haven't emphasized on her dojutsu for the emotional,love,pain or loss to gain these tomoe is weird..
Maybe it was a drawing error cuz the novels don't make her case as that's a different story base for her growth then the manga or anime