I sure hope you are quarantining these rats ina seperate household with a different air supply if one is sick. Sendi and SDA are very highly contagious viruses and spread rapidly through a rattery! They spread via air so even if they are contained ina seperate room they can still infect others. These virus' also stick to hands and clothes so you need to make sure that you wash your hands EVERY time you play with rats at the petstore and change your clothes. These diseases can wipe out a rattery within a week!

If she is sneezing she needs to see a vet. Contrary to what people think, it's not normal for rats to sneeze, at all. If not a contagious disease sneezing can be a sign of a MYCO outbreak, which can be deadly if left untreated. Flareups in MYCO prone rats are common, but should always be dealt with swiftly. MYCO can scar the lungs, making it very hard to breathe. This calls for a dose of antibiotics such as Tylan or Amoxicillan. It's not reccommended to use Baytril on kittens (baby rats) because it stunts their growth. Try less invasive antibiotics first, and then if that doesn't help try Baytril. PLEASE quarantine new rats for a minimum of four weeks.

I hope you got the same sex. Breeding unpedigreed rats is a very dangerous thing to do, for future ratties because most petstore rats are prone to diseases as well as tumours. If you do have opposite sexes keep them seperated!

P.S. Your gray girl is referred to as "blue". Other names: American blue, sky blue, Slate blue. Your brown girl is most likely agouti (wild coloring) or chocolate. Hope to see pics soon and I hope you take your rat in for treatment.