Your stuff is so cute!! I would definitely say your jewelry is NOT overpriced, seems fair to me!
Shipping is so hard these days, but just make sure you are charging enough to really cover the cost of shipping and shipping supplies. You HAVE to protect yourself in this way. Try to calculate the cost of shipping as accurately as you can, your buyers will understand that the postal system is expensive these days!
For only being open a month, I'd say your doing great as far as sales go. Just keep up the good work!