i will definitely debug this once i have the time. but to answer your question, yes i had both a child and adult portraits. as i did realise the filtering would indeed pick an adult one if there was not a child one.
the way i'm testing portraits is, making a a new sandboxed game, customize start and make my start slave whatever race / age and so on what i want. i'm also making the amount of portraits in the portrait folder for that race smaller to make sure if it's working or not. So if i want to check if it's picking age, i'll mostly only have one adult and child one. as it should be only be picking one of the pictures. when i tested breast size, i had 4 different portraits with different sizes but all adults as i could just make the starting slave, adult, so the age wouldn't matter. i'm probably going to do the same thing with 0.5 when i'm going to debug, if there's anything wrong with this, do let me know :)