Woman refuses to give older sister 'heirloom' necklace for wedding, 'grandma said it should go to ME.' AITA?

"AITA for refusing to give my sister (27F) the 'heirloom' necklace for her wedding when my grandma (84F) said it should go to me (22F)?"

Okay. So this might sound petty, but it's turned into a whole family drama and I need outside opinions. I (22F) was really close to my grandmother growing up. Like, she practically helped raise me.

My parents were going through a messy divorce for most of my childhood, and I spent a lot of time at her place just to have some sense of stability. We baked every Sunday, watched old black-and-white movies, and talked about literally everything. She’s always been more of a mom to me than my actual mom, tbh.

She has this necklace—nothing super fancy, but it's antique gold with a little sapphire pendant. It originally belonged to her mother, and it's kind of a family “symbol,” I guess. She told me for years that she wanted me to have it. She even wrote it into her will when I was 16.

Fast forward to now: my sister (27F) is getting married this fall. We have never been especially close—different dads, lived apart a lot, etc. She’s always been the “golden child” in my mom’s eyes, though.

A few weeks ago, my mom called me saying she was helping my sister plan her "something old, something borrowed, something blue," and they wanted to borrow Grandma’s necklace for the wedding. My mom said it would be so "special" and that Grandma would love seeing it walk down the aisle.

I was like, “Wait, you mean my necklace? The one she promised me?” My mom got annoyed and said it wasn’t mine yet, since Grandma is still alive, and that I was being selfish not to let my only sister wear it on her wedding day.

So I asked Grandma directly. She got this quiet look and said she didn’t want it loaned out, because she’s still planning to give it to me on my birthday this year and didn’t want it “passed around like costume jewelry.” Her words, not mine. I told my mom and sister this, and they completely blew up on me.

Now my sister is saying I’m “jealous she’s getting married first” and that I’m “punishing her for being loved.” My mom keeps calling me cold and ungrateful. Even my aunt texted me saying I should “just be the bigger person for one day.”

I don’t think I’m wrong, but now the whole family is basically icing me out. So...AITA for not letting my sister borrow the necklace my grandma specifically said she wanted me to have?

Here's what people had to say to OP:

Mysterious_Peas said:

You’re not wrong and NTA. Unfortunately, it is highly likely that if you loan the necklace to your sister you will never see it again.

Momjamoms said:

NTA. Its literally not your necklace or your decision not to loan it. Why aren't they talking directly to grandma?

alien_overlord_1001 said:

NTA but you might want to check where it is - sounds like it might go missing just before the wedding. If gm would “love to see it walk down the aisle” then she would have offered it.

Son0f0din42 said:

NTA. You asked grandma, who wants sis to F off. Done. Little curious why grandma can't say this to the rest of the family (and/or why they aren't listening to her)? Seems like this situation shouldn't be involving you at all (from anyones perspective) if the jewelry isn't yours yet anyways.

OglioVagilio said:

NTA - it doesn't matter we what you, mom, sister wants. Grandma is still alive. It is her necklace. She said no. Your family is crazy.

LanaRunaway said:

NTA..trust me, you will never see that necklace again if you let your sister. You grandma doesn’t like the idea too.