Anyone else have this issue?

Back story; she’s my husbands half-sister, they are not close at alllll. He can’t stand her bc she lies a lot and always wants people to feel sorry for her. Back to the story, when I got pregnant (I didn’t know I was pregnant at the time) she completely went off on me bc I didn’t agree with how her boyfriend talked to me or how he talked about my husband (her brother) he called my husband a fat ass bc the field wasn’t cut at our house and the grass was tall 🤦🏼‍♀️ Anywaysss, so she tries to be all goody goody with me when she finds out I’m pregnant, I invited her to doctors appointments repeatedly and every time she was always “busy”. Well, Addalyn is 8 months old and his sister has only seen her once and only lives 20-25 mins away. Only time she saw her was 2 weeks before Thanksgiving and she was 5 months old. She never came to the hospital nor came to visit when we came home. I never got a text message, call, nothing. Well, Addalyn shortly got RSV the week of Thanksgiving, never heard anything from her or his mom checking on her. She texted me 2 weeks after Addalyn was over RSV asking how she was. She would post all over social media acting like she was the best aunt ever and was so involved into Addalyn’s life when she wasn’t, which his mom does the same thing. They act like they’re around her 24/7 when we have family gatherings. But in reality, she’s seen her once and his mom has seen her 4 times (3 times being Holidays at his papas) I ended up blocking them from Addalyn’s updates/pictures on Facebook but still remaining friends, so that way, they’d have to ask about her; it’s her only niece (she doesn’t have any nephews or kids) and it’s his moms first grandchild. So you’d think they’d actually ask or check on her. 2.5 months went by and never once did his sister or mom ask about her, so I deleted and blocked them off Facebook. They’ve been blocked for over a month and just now realized. I’m sure someone else is going through this with a family/friend. If you don’t make yourself a priority into her life and check on her once and never come see her, since she’s been born obviously, I don’t want you seeing updates of what you’re missing out on and just watching her grow up on social media. Sorry to rant/vent and it’s super long. So thanks for reading if you got this far, but tell me i’m not alone. 🤦🏼‍♀️🙄