Well, I have a pom so I know exactly what you are going through. Daphne was our world and still is, and so she was so confused and jealous when Tay came along. She actually hated her at first.. then it moved to where she *tolerated* her as long as Tay didn't bother her.. and now well she really adores her! Of course its on *her* terms and when shes in the mood, but she hardly snaps at her or anything anymore.. just barks or growls to let her know shes grumpy and so forth.. now Tay listening is another story. But Im one with the story with hope that it does happen! Daphne was and still is a spoiled brat and we didn't know how bad til we got Taylah.. but she knows tay is her little sister and she needs to share us with her now..
. Hang in there, hopefully it gets better!
Also wanted to add, Daphne (pom) will be 4 years old in January, is 5lbs and it took her about 2 months to get to this point!