Sister ruining wedding

I'm so sorry you're going through this. To a lesser degree my older sister also was really offended that she wasn't a MOH. She's already married and had her vow renewal without ever having me a part of either. But when it came time for me to get married, she first pressured us into having a big affair. But we decided to go more intimate - only immediate family and best friends as bridal party. She was so hurt that she wasn't MOH. My sister started to try and work around it by ordering my actual MOH around on events, chose the same color as the bridal party, etc.

My advice is to not to feed into it. It can be so stressful, but by trying to appease her or solve the problem before she is ready to resolve it - you'll just escalate the drama. She can either be an adult or no. Once she calms down and is ready to work with you, you can plan a fun 'just the two of you' bonding wedding event.

Ugh. Had a similar situation with my cousin. I told her if she didn't like she didn't need to come at all! She started screaming and the works but I walked away and said fine don't come!
No complaints sense. 🤷
That's super embarrassing your sister is nearly 30 and acting like a child, you are such a nice person to have even kept her as bridesmaid! I didn't even include my own sister but she's not as dramatic, just not very responsible.

She sounds kind of jealous.
I agree with what PP said about not appeasing her. it's your wedding... Have and do what you want. If she's truly your sister and there for support then she should follow along and be happy for you and support you anyway.

She is using her tantrums and anger to try to control you, and family telling you to accept it or appease her to keep the peace is probably part of how she got to be this way. No. Do not allow it. The next time she says something angry or nasty about your wedding, breathe slowly, and in a quiet but firm way, tell her, anyone who is as angry and rude to me about my own wedding, should not be in it. You are no longer a bridesmaid. . . . You do not need to give her more chances. She blew through them already.
. . No matter how many times already married people post on here that the traditional practice of not naming a bridal party until nine months out, or absolutely the latest, 12 months, newly engaged bride's forever say, it is different. I know my ladies, nothing will change in _____ ( 15 months, 18 months 2 years.). Since you say this has been going on for a year, and it is now 1.5 years away, you asked too soon. You cannot undo it now. But other newly engaged women take note.
. . 9 months time leaves long enough for any friend and family drama. You can ask any friend or family to dress shop with you, before you choose a wedding party. And share any news you want to. Because they are friends. And there is nothing a bridesmaid needs to do wedding oriented until 6 months or less.
Bridesmaid dresses come in so quickly, 2-10 weeks, and if ordered at 4 months out or less, need free alterations. . . . Having a wedding party and expecting everyone will keep up their excitement and interest all along, no squabbles, no drama, no life ng periods of not seeing you, for more than a year, it horrors, 1.5 years or more, is like planning a birthday party for 8 hours for a 6 four year olds with 1 mother. There is no way there will NOT be drama in that long a time. None. And with adults, there are always some life changes: moving, getting engaged themselves, new SO who becomes the one they spend 98 percent of their time with. Then, pregnancy. Or just a falling out, or loss of feeling between you and them. . . If sis pulls this again, don't accept it. And think of how unfair it is to your sister who is being wonderful, but Ms. Nastiness gets all this nice accommodation. WIt til she pulls something again, and drop her on the spot. And tell everyone, you will choose any non- family bridesmaids between Jan and June 20 20. And stop sharing details where troublesome sister will hear if it. . . . My mom comes from a large family, has 4 sisters. Their mom had four sisters. Who are mothers of 31 of the 35 female first cousins who live and grew up with a fifteen minutes drive of me. And I thank heaven, it was a blessing at wedding time, that my grandmother's mother taught them to never choose more than one sister, or cousin, or in-law to be in a wedding party. Because then all the Dynamics if any family if 3 it more kids if one gender come up. Older one has control issues. Two sister oppose the bride, you have a mess. Bride is easygoing, but 2 through 4 sisters old jealousy and control, shyness and dominance, come into play, and the bride can never have it about her wedding without drama. And any 2 sisters always know better and more about bride than any best friend or in-law , so there is suddenly drama to assert position.
. . I am so happy we were raised to think, only one family representative, or none, in a wedding party. Saved my wedding. Easy peasy. And as for hubby's then 5 sisters and 5 SIL ( others working overseas) ? No. Just, I am so thrilled you will become my new family. But bridal party are the last signs of the friends I had while single. And my Godmother "auntie." You deserve a wedding free of this miserable drama. Pick a good friend, under 9 months out. If Ms. Nasty has not called down to being a civil guest by wedding time, --- well she does not have to come. She only will miss due to her own bad behavior. And the world won't end if she does not come. You would not cancel if she got her appendix out 2 days before, or if a new job required she work that day, right? Her presence is nice but not necessary. And once you get that, she has no power over you.

I really like what Judith said about “her presence is nice but not necessary. Once you understand that, she has no power over you.”

I would consider practicing a boundary-setting line and say it the next time she acts up. Something like (in a firm voice): “Stop! I’m tired of your negative comments about my wedding. I love you. But either stop with negative comments or you’re out of my wedding. Your choice.” Something possibly like this. Something that says stop now or by her choice she won’t be coming. She can throw a fit. But if she continues there will be consequences. I’d also stop sharing details, even if she asks.

I'm so sorry you're going through this, weddings can bring out the worst in people. IT sounds like she's just jealous and is being petty. You keep planning your wedding and let her throw her temper tantrum.

It sounds like you should just avoid her for now, don't see her, keep her out of wedding planning, etc. If the behavior continues, I'd seriously consider not having her a your wedding.