Jealous dog biting other dog?

We have a pekingese and she isn't our first dog, she's the second. We had a boxer first who she didn't like because she found her intimidating but the boxer liked her and tried to sleep next to her or play with her. When the boxer died we got a jack russell/chihuahua. The pekingese like the jackhua until t got older and started tearing up the house so we put her out side, she got pregnant and ran away. We had to give away all 3 puppies. The next and current dog we got is a chihuahua/poodle. For some reason the pekingese hates her and if I pet the chipoo she stares and her and grunts and when I put her down she either smells her or bites her. I don't under stand it though she didn't bite the boxer, the jackhua, the jackhua puppies, or the cats outside. She just hates this particular dog and the chipoo isn't vicious. Its skittish and hides from everything. How do I stop the biting and jealousy?