Welcome to YT! I was told to keep the upper third trimmed to prevent Toto's little ears from flopping back down. When your baby's hair on top grows longer, you will need to band it to keep it out of her eyes and enable her to see. You could keep it cut short if you prefer. I was also told to avoid cutting it really short around her eyes ... the little stubby hair can stick in their eyes and cause eye infections.
We have some excellent breeders/groomers here who can give you good advice. I hope you enjoy the forum, we would love to hear all about your baby and see pictures!