"My sister is a model."
Translation:Minha irmã é uma modelo.
I really hope I'm not wrong, but I don't think I am. This is a cognate with Spanish. It's just one of those that don't follow the rules but are just what they are. "Ela modela" would mean "She models". U can also use it for male. "Ele modela". It's a verb. That's why it's in the drop down :) I also chose "Modela" and then I thought about it :P