Kate,
One of my hypo bloods is also exhibiting the type of pattern you're talking about, but I think it comes from the boodred lines more than anyhting else, because I have seen bloodred outcrosses even showing the same thing.
The only way that you could tell would be to breed your little gal to a motley to see if the clutch has a significant representation of motley babies. I say "significant representation" because even the outcrossed bloodreds will show some clear bellies at times.
Personally, I don't believe that there is any way that these babies are het for motley. The reason I say this is because I have seen Rich write about what a waste of time it would be for him to cross the two, because in the F2 you could never be able to say for certain whether a baby was a motley, a bloodred, or a bloodred motley and those couldn't easily be sold. So, I don't think Rich would knowingly introduce motley into the bloodreds, let alone the hypo bloods where each one was so sought after!
Just my two cents' worth --