I hope that you do realize that hairless rats do NOT breed well and will usually not lactate, which means the mother will kill off the young. The birthing process also doesn't go well the majority of the time, usually resulting in the mother hemorrhaging and stillborns.

If you want hairless, breed the male hairless to a normal, haired female, and then breed the resulting females back to the father. This results in lactating mothers, healthier, bigger babies, and no killing of the babies. Since the first generation carried the hairless gene, but looked normal, breeding those females back to the father would result in about 50/50 hairless and normal that carry the gene.

That would be the best way to get hairless rats if you must have them. True hairless(hairless x hairless) are generally not healthy and do not have good immune systems, which results in alot of respiratory difficulty. I have a true hairless female here and she has alot of eye problems.

Please do not breed that female. It won't be a good outcome. Not to mention rats shouldn't be bred until they are at least 4-6 months old, depending on size and weight.