A. Not making tears is rarely a true medical problem, especially since you don't mention other symptoms.
Newborns start making tears when they are about two weeks old, but often it is just enough to keep their eyes moist and not enough to make real tears that you can see when they cry. Infants often don't develop real tears that you can see until they are much older and about seven or eight months old.
Since that time is just an average, you could expect that some infants might not start making real tears until even later, so 9 months may still be normal. And if your baby truly wasn't making any tears, then her eyes would likely be very red, dry, and irritated.
In addition to simply not being able to make tears, an infant might not have tears if they were dehydrated. The fact that she is only having 3-4 wet diapers and her lips get dry quickly also might point to dehydration as a problem. Still, if she were truly not getting enough liquids, you would expect that she would also be losing weight or at least not gaining weight well.
Has she been gaining weight normally?
Do you give her any extra water or one hundred percent fruit juice?
Have you noticed any decrease in your milk supply?
Keep in mind that not making tears is usually a late sign of dehydration, after infants have lost a lot of weight, have very decreased urine output, and may be less active. Since you mention 'no other medical problems,' that would all go against her being dehydrated.
So the basic answer to your question - 'Could she not be getting enough liquids or is something else going on?' - is that she is probably fine, especially if she is gaining weight well, but you should likely see your Pediatrician for an evaluation to make sure she is drinking enough. A log or diary, where you record when she urinates and what she is drinking, might also be helpful.
