Nothing at all wrong with first time rattie moms doing 9 or 10 babies. I've had some that only delivered 6 or 7 the first time up, but then consistently produced much bigger litters thereafter. I always like to give a female rat at least two or three runs through the breeder tubs before I decide if she's really not producing up to expectations. I had one produce 2 pinks for me yesterday...2! She's had a litter before so I'm not sure what's up but I fostered them off to a nursing mother and put that female back in the female tubs to rest. If she produces low again for me...she's a cull.