My baby biota venustus angelifsh is getting a white band between her blue tail and yellow body, anyone seen this pattern before?

[Demogorgon]

It had a white patch on both sides of her tail, in the last few days the white band is growing. Is she a possible hybrid?

 

[Gumbies R Us]

Do you have a closer picture?

 

[Demogorgon]

Do you have a closer picture?

I have this one.