A BP missing a meal or 2 is nothing to worry about. From what you've posted, I'd guess the reason is that the meals you are giving her are too large. BPs will often take a break from feeding if they've been eating a lot, to sort of even things out. Many people report that their BPs eat more consistently if they are given smaller meals.

I'm more concerned about why she would appear dull and sandpapery so soon after a shed. The first thing I'd try is to increase the humidity or offer a humid hide.

How and where are you measuring the humidity? If you are using one of those dial gauges, it may not be accurate; digital ones are MUCH more reliable. Or if you aren't measuring it at the correct location, it might not represent the conditions the snake is actually experiencing. Many people make the mistake of putting a thermometer or humidity gauge halfway up the side of the tank, like you usually see in pet stores, but snakes spend very little time halfway up the tank.

Winter usually means drier air, so that might explain why she is having trouble now when she wasn't in the past.