Hi Dekka's owner,
I wouldn't worry about Dekka or Dekka's mom. Uneven number of nipples are normal for dogs. Some dogs even have oddly located nipples scattered around their bodies. As long as none of the nipples have swelling or abrupt changes in color, then you shouldn't be worried about the oddity. It makes them unique and makes quite a good conversation starter even.
Best of luck with Dekka and the fam.