Nice training job on that girl.
I don't see 3 cotyledons on the seedling though.
Counting, lol... true polyploid seeds have an EXTREMELY low germ rate, like 1%, it's outrageous... in advanced somewhere there's a writeup on the experiments with chemically forcing polyploidy. The chances of getting one that survives are slim to none unless you are germing hundreds of seeds that have been treated with colchichine.