Even drawing a rotated ellipse is so difficult for beginner!

[kenny1999]

I wish to draw a rotated ellipse, on top of the picture of a wrist, as shown below.
I am able to figure out how to draw an ellipse and rotate it, but the inner area
of the ellipse is white and would hide the hand.

Below is an illustration of what I want,it's hand-drawn, but I need a perfect 
rotate ellipse.

Please step by step or highlight the key step for me and I figure out the details, I am so frustrated as an amateur beginner of GIMP