A vet would be a better choice for a "check-up", not a pet store where they could be exposed to other illnesses and parasites. Especially since pet store workers don't have DVM behind their names, or have veterinary training.
To me the female looks underweight - you can see her skin folding some in the pictures.
A fecal exam costs about $20 and the treatment is about $5 a dose, if they test positive for internal parasites.