It's impossible for me to be sure (from that picture & just online) but it appears to be a fungal infection of some of her scales. I've had a BP that had the
same thing (long ago) & I got a topical anti-fungal medication from the vet to treat it. It's not an emergency or terribly urgent...but if my guess is correct,
it will spread to more places on your snake & be harder to get rid of. Your call. You'll notice it didn't go away with the shed, & if you look close, you'll see
the scales in question appear dried & shriveled-up. You can tell it's not a normal scrape, those improve with sheds; if it's what I suspect, it's fairly distinctive
because the scales are individually abnormal, whereas other kinds of damage (scrapes etc) aren't like that. It's not hard to treat & get rid of, just easier when
it's not all over their body. I think BPs must be prone to it (with their warmer & humid enclosures) since none of my other snakes have ever gotten this,
not once in all the years I've been keeping quite a few snakes.