since anon wondered “how she so impossibly thicc?!” This is how I have figured it. 

*edit, added some shading to some of the tail bones to better separate them for the viewer.

last image in the line demonstrates that the tail doesn’t have very large footprint on the hips, it is mostly tendon there, and then it rapidly expands to make room for both muscle and fatty deposits feeding the muscle energy and storing heat.

the tail has fairly large bones as it is a remnantr of bowsers previous form, and it was not only for balance but one of his melee weapons.

also, it’s why her hips are even more wide set than most other peachified characters.