There are some "incomplete" pearl cockatiels. These birds can appear like normal birds with a few pearled feathers. Genetically speaking, they are visual pearls, but they don't look like it. Bananas is definitely a pied, and has some female markings, however that doesn't say much due to the fact that male pieds can retain certain female markings on their feathers. I'm not entirely sure Bananas is a pearl pied, but I think I see pearl markings at least on the wings, and I think those are pearl tail feathers, too.... the yellow ones.
If you went in to the vet for blood work, you could always ask them to get a little extra blood for a DNA test and they might only charge you a blood collection fee? I think the companies that do DNA sexing on birds charge vets the same price as they charge us, so the vets need to make some amount of money from doing the DNA sexing for you?