My Dad is very happy about my pregnancy, but his younger longterm partner has issues...
We usually gt on well and she's been with my Dad since I was a teenager. Since I told her I was pregnant she has stopped being in contact with me. Dad says that she is jealous because she has wanted another baby for about 8 years but he doesn't (their daughter is now 9). Dad says he can't mention my baby in the house! My half sister has no interest in the baby and its all making me feel a bit sad and neglected.
Not sure how to address the situation... Should I speak to her?
That's a shame, I can see why she might be upset if this happy news hits a nerve but I hope for your sake she comes to accept this and not spoil your dad's excitement and anticipation. Do you have other family members to celebrate your news?
I don't think I'd raise it with her on your own, I think she'll either come to terms with this by herself if you've had a strong bond before, or maybe your dad will discuss it. If there is quite a big age gap between your dad and his DP I guess it was inevitable you might yourself become a parent and he in turn become a grandfather, before she had given up the dream of a second baby herself.
Don't rub it in her face, so to speak, (I'm sure you wouldn't anyway), just focus on you and your health and hopefully by the time your LO arrives, she will have come round. Girls your half sister's age are often assumed to be cooing over babies, they're not always, and she'll probably follow her mum's lead regarding enthusiasm or interest for now.
One of the first things to remember when you are pregnant is that many people will struggle with the news. You can't know who is suffering their own anguish over the child issue, whether it be a partner who does not want them, an ability to get pregnant, miscarriage, Ivf failure.... there is a long list. Most put a brave face on it, but some can't.
Try to be understanding and not hold this against her. She is hurting, and your situation is hard for her. It isn't personal.