The bottom point comes to just above the knees and the the sides are midway to the thighs. Thats just me though, if you are very tall it will look different.
Unfortunately I am a size 1 so I couldnt tell you for sure if it would fit 7/8. The girl who gave it to me was about that size so I would assume 7/8 is a close fit. You could always open the seam and take it in. Plus, its stretchy.