RANT!! SIL DRAMA!

So my SIL who is already married is renewing her vows sept 12!  She never had a wedding first time around so she's going big now. I am due sept 28 however. Before my hubby and I found out the due date he accepted to be a groomsman and be at the wedding.  I have had some complications and dr will take out my cerclage at 35 weeks and said women usually go into labor around 7 days after!  That puts delivery first week in sept!!!  Now they live in San Diego. And we live in Las Vegas. We have kept them informed along this struggling journey. However today she called and said she has chosen him to officiate the wedding so can she deffininavely count him as a yes. He was honest with her and said I don't know if i could I would but it is tight.  He said he can't make promises when all is uncertain.  He would rather be upfront with her not then tell her 2 days before the wedding. She went on to tell him that he's an asshole and a horrible brother then her husband got on the phone and yelled at my husband some more. I yelled in the background he is not going to miss the birth of his son. HIS FIRST BORN!  Then they continued to hang up on him. My hubby is such a pure heart he cannot fight with them and doesn't stick up for himself or us. She is so selfish for making him feel like this!  He is the eldest brother of 6!  And or course she is the baby. Ugh it's so frustrating!!!  It's not even a real wedding she is already married with 2 kids!!!  She has no care for our baby or what the family is going through. A used my hubby of ignoring her this week ok his step dad was in town and his step dads grandma died and my SIL yelled at him for not keeping in touch. Ugh I just wanna yell sometimes sorry rant over!!!