Everyone is making princess boo a very busty lady, but I much prefer her being a shy petite lady. Then again, it makes sense for her to be a bit bigger since King Boo is bigger than other boo. Maybe if a regular boo got a crown, would this be a more likely result?
I envision her like a slime, she can increase size/bust. Like she sucks in air and puffs up to increase size, and then can exhale everything and slim up.