I'm not really sure what the official name for this hairstyle is. Like I've said before, I'm no hair expert. But, my princess says it looks like a basketball net, so we'll go with that.
Start by making a part all the way across the top of her head. Divide this section of hair into five little sections and make little ponytails with colored elastics. Then, make another part across her head about an inch below the previous part. Divide this section of hair into four small sections. Combine the ponies on top with the ones you are making underneath, by splitting the top ones in half.
You could do any amount of ponies you wanted, or as many different rows as you have the patience for (alternating between adding a pony, and taking one away every row.)