I saw your photo and I think she looks just fine. Absolutely normal for a boxer pup, and not at all excessively ribby. Remember that it is far far better for a puppy to be on the thin side, than ever to be chubby. That round puppy shape is not supposed to last past absolute babyhood (and if it does is often an indicator of worms LOL). It is not a good thing to try to put weight on pups - it usually simply results in them growing taller faster (and that's not good). Just let her grow up naturally
As for the peeing - actually she may be awake, just not crying to go out
But puppy bladders grow at different rates, and most will need a couple of potty stops per night to stay dry. Try setting an alarm for a couple of times each night to take her out and see if that doesn't help matters.