My GF has an adult male thats around 1200g that fits in the mediums. He is too fat to get into the opening without lifting the hide up, but he is able to get under it without any problems. My male thats just under a year is at 500g and isn't even close to outgrowing the medium RBI hide. Unless maybe their sizes have changed over the years?
Either way, coffee bean is awesome! I think I remember seeing a post about her taking a strike at you. Has it happened multiple times?