Should I be able to feel my kittens spine and ribs?

Well I got two kittens at 5 weeks old and they were both VERY skinny and scarred, it's normal there young and haven't grown much, at almost two my little girls(kitties), are both still very skinny and that's just how they were born, and the whole coyote thing I'm moving to Arizona, do you know of Gilbert that's were I'm moving and do coyotes go in backyards there because I would FREAK if my cats were attacked by a coyote sorry about the question but just curious.