2 Half-Knots With A Messy Pony

Part the top to the side or middle, then part all the way across her head forming two sections. Pull the rest of the hair back into a pony and don't pull through all the way the last time through the elastic. (As you can see, her shirt is wet. This style is easier if you get the hair soaking wet before you start.)

You're going to take the hair on one side of the part, split it in 2 sections and tie it like you are starting to tie a knot. (Or a shoe.) Take the 2 ends and put one over the top of the pony and one under the pony. Wrap them around and secure with an elastic.
Do the same thing to the other side.
To finish off the pony, it all depends on how long her hair is. If it's on the shorter side.....just tie a bow around what you've got. If it's a little longer, you'll need to pull the end of the pony up and through the elastic again, like we did here. You can't see it in this pic. but, there's a loop of hair underneath.