All good comments.
I am one that does believe bodyfat is a valuable measure, but I am the analytical type. I would think calipers or water testing would be a better way to go, do it at the beginning of a focused rotation or eating plan and then the end. To see if you are making progress. When measuring my progress I look at my weight, bodyfat and also how I look in the mirror. All are valuable feedback, IMHO.
That being said, I do believe that you can be a petite light weight person but still have a high bodyfat. The world is full of them. I am a recovering one! I would classify myself as a "skinny fat" person. My weight is pretty low for my height, I am a size 4 or 6, but my bodyfat has never been all that low and as a result, you can't see my muscles all that well. You can...SOME. And you know, I am well...skinny. But not the muscular definition I see in Cathe or Jai or whatever who have low bodyfat. I am working on it, of course!
Went to a nutrition clinic where they said "The world is full of size 6 women with 35 percent bodyfat" (meaning, that is not healthy).
Not trying to say that your situation. Just food for thought.
Jen