So you want this kind of?
You don't have off camera flash? ugh...
The shot itself is pretty easy to set up.
To get that sky exposed right you need to get your camera to think it's the sky you want exposed. This should then give you a pretty blue sky but dark character.
You could use a reflector to bounce sunlight back into the character.
The flash duration is what freezes the action so there is no motion blur.
If you have on camera flash you might get lucky.
You need to go into P mode on your dial.
aim the camera at mid tones in the sky to get exposure readings.
set it up in manual based on those settings and now you must get as much light on talent as you can. Plus freeze with on camera flash? might work. maybe tough though.
the goal is to get sky and character both exposed so good luck having a camera's auto exposure figure that out.
body proportion problems or wide angle distortion is probably a distance to camera thing.
Obviously you need to have sis at a low angle shooting up at you with only sky as background. she might be too close to you.
good luck! sounds fun but be careful.
It would be so much easier to just get on a plane, come over and we'll do it here : )