Though the actual size might show up differently depending on your operating system because of different implementations of MB and MiB. On Windows you need to look at the "Size on disk" parameter which you can find under the General tab in the properties menu.
For a mildly more serious response: The notion that Corin is 16 comes from an accidental leak where someone posted a lore handout about Corin to the official Twitter. Similar handouts have been leaked for a small number of characters like Burnice and Caesar. It turns out that they're voice acting demo instructions, not canon pieces of info.
I find it very strange that Corin's is the one people became obsessed with when it would otherwise be pretty weird for Caesar, Burnice, Ellen, Billy, Nicole, Grace, and Anton to be the exact same age.
