Nah the earliest she could get her 4th is 19
Which is a Master rank?
I just looked on the ATA website and they have tournament brackets for ages 1-7 up to 3rd degree. And there are names listed.
I've been to a TKD tournament where there was a category for 8-10 year old 3rd degree black belts. There were entrants.
Unbelievable.