Out of pity she got included in the character presentations cuz all her other sisters did
If you are wondering, Google translate says that her presentation just calls her weak, same as the earlier volumes, not even implying she got stronger alongside the Bug devil's that are related to Famine
(left scan is from CSM Chapter 132, Page 6, and right scan is from Chapter 135, page 5)
basically, Falling Devil, just by her Mere presence was causing Gravity fluctuations around the world, with her presence being for a short time of likely less than an hour (was ´´dessumoned´´ by Fami after she failed to make Justice Devil eat Asa Mitaka)
some details of the feat needs to be considered, it saying ´´Falling devils appearance are triggering cavein and landslides one after another across the world!´´ this means that all the destruction she could had made or all the mass she could had lifted was overtime, not all at once
second, Yoru says ´´Falling devil mere Presence temporarily reversed gravity in places all over the world´´ it says ´´in places all over the world´´ this means not every corner around the world got affected, so she wasnt lifting every single building of every single city around the world, this becomes clearer with how Japan itself its still intact, Denji and Asa can still go to their school cuz it wasnt destroyed
even then, she says all countries become poorer, so even if not all corners around the world, it did affected parts of every single country around the world, even Brazil (the furthest country from Japan, and from Tokyo, even over 18000km)
so because of that, i assume it´d be better acting as if Falling Devil affected every corner of only one nation, examples could be Japan (takes only 0.25% of the land of the world) or USA (takes only 6.1% of the land of the world)
but besides this, i found out just dividing the weight of earths landmass (5.972e24 kg) by how much of the land it takes certain nations (japan and USA) would be assuming that Falling Devil lifted the whole country with all the elevation from sea level (japan for example has 438 meters of elevation from sea level)
definitively Falling Devil didnt did this, lifting hundreds of meters of multiple areas around the world is exxagerated, i assume the feat is more likely lifting multiple buildings of cities, the trees of forest, and smaller rocks (not even close to mountain size) to cause those caveins and landslides that makes all countries poorer
so for that, id think if there was some data of the weight of certain cities/forest (only buildings, trees and more) would be more accurate
i got a calc in vsbw, its work in progress