Your pup isn't weird - eating from a comfortable position is very sensible. If you think a little about it, or perhaps think about nature programs you may have watched, you'll probably recall that most carnivores eat lying down
Dogs are no exception, even if we're used to them consuming kibble from a standing position - give them some natural food like a hunk of meat that they have to spend time chewing, then the majority will sit/lie down to work on it. I think they're quite well adapted to digest their food this way
so I wouldn't be concerned with your puppy doing the same thing, even if it's kibble she's consuming.