My husband's ex girlfriend...help!

My husband has two boys with an ex girlfriend. They are 11 and 12 years old. We have a 3 month old baby girl. Now his ex girlfriend had a baby girl yesterday with somebody else. My husband's sister went to visit her at the hospital and was posting pictures of her baby all over facebook and telling her she is going to need a regular visit😑 she has came to see her own niece ONCE! She has posted ONE picture of our daughter. His mom, aunts, cousins posted on her Facebook how they were dying to meet her baby girl. I honestly try to not pay attention to it but it bothers me so much. His sister even wants to go to her wedding because she is so important to the family. His mom blocked my mom on Facebook because she has pictures of MY husband with his ex at different events while me and him were together. He asked his mom to delete those pictures because they were pretty much screaming "CHEATING" right in my face. But instead she rather block my mom so she wouldn't see them and keep them on her Facebook because "they are memories to her and her family." They are not pictures of her and his ex or family and ex. They are pictures of my husband cheating pretty much. I forgave him for that and moved on but I feel extremely disrespected and disappointed. His ex's new mother in law is always there for her, so is her boyfriends family. And I get to have a shared family. I'm so frustrated and angry. I really need advice. Thanks ladies!!