two puppies

Question
I have two Australian cattle dogs and Maya the 8 month female is not eating and is acting a little weird. I have read that when you have a new puppy show the first one more attention so she don't feel left out or not loved. Tyler the 3 month male is a lot more dominant and just act like a puppy. She has always been a little sensitive about everything when they play the really play she seems happy. I feed her first then him i keep them apart while eating i don't know what to do i don't want to jack her up please let me know what i should do  

Answer
If she isn't spayed, she could be coming into season.  If so, almost any behavior could be expected.  None of my Labs have ever quit eating, but I understand some dogs do.  If her vulva is starting to swell, most likely that is it.  The second and third weeks are when the most risk of accidental breeding is. Don't take this lightly. She will do anything to get loose and get to a male. Once loose, an accidental breeding and an unwanted litter is far from the worst that can happen. Such breedings can also result in fatal infections. She can get killed when she dashes heedlessly across the road in front of a car. Other dogs or coyotes may kill her.

Otherwise, you have the vet take a look.