They will get along with her, it will just take alittle time....I have 3 cats, 1 diva cat, 1 cry baby, 1 bad a, they all weight twice as much as Lexie or more...She is the cat chaser, she jumps on them from the bed, she chases them around the house, and she sleeps next to them in her bed..(they all want in her bed) It will just take time...Most dogs know how far to push, and sense when to stay away, she is still a baby give her time...but please please don't declaw your cats...The cats maybe alitte jealous of the new baby too. If you have had them that long, you know how cats act...