Hello and welcome to Just Answer. I am a licensed veterinarian and would be happy to answer your questions.
Is her coat getting too thin in any area?
Is she itching or does she have any lesions on her skin?
Do you brush her regularly or take her to be groomed?
Are there any other changes with her (eating/drinking/elimination behavior)?
Thanks and I will respond when you reply.
Sometimes, especially if they are not brushed regularly, they can have a normal shed of their undercoat that seems to come out in clumps. That doesn't sound like the case for her if you are the diligent in brushing her.
If her hair is starting to thin out, it would be a good idea to have her examined. There are various disorders that can lead to hair loss including hormonal problems that involve the thyroid or adrenal gland, parasite problems, fungal problems (like ringworm) or even skin infections or allergies. After a thorough physical exam, your vet will have a better idea of what else if anything needs to be considered as a possible rule out or if this could possibly be normal for her. It sounds like it is not a nutritional problem as she is on a good diet. Sometimes supplements like a fish oil may help, but I would at least have the exam first before introducing any oral supplement, especially since she seems to have a sensitive stomach.
I hope that helps. Please let me know if you have any further questions.