Just looks like nice muscle tone, low body fat, and killer obliques to me haha.

She obviously works out, you can see some pectoral development as well.

She has spoken about working out a lot and apparently used to do a lot of kickboxing as well so that could explain the strong abs etc.

http://en.wikipedia.org/wiki/Inguinal_canal

"The inguinal canal is a passage in the anterior (toward the front of the body) abdominal wall which in men conveys the spermatic cord and in women the round ligament. The inguinal canal is larger and more prominent in men."

I think what you're really seeing is just the development of the muscles and pelvis bones. It's purely genetics in that case, where the definition of those bones and muscles is at.

Also, it may just be a body type thing. For example look at the general shape and build of Ryan Reynolds and Hugh Jackman (first two names that came to mind, no homo haha)



now look at the placement of the pelvic bones on Hugh Jackman



You can see where his definition start a lot closer to his waist line.

Ryan Reynolds seems to be more on the ecto side as well, so it may be possible that people with this type of build tend to have that feature be more prominent.