Flaky & Confused Bride

Could you start by telling your parents this (separately) - that you are feeling really anxious that people won't behave at the wedding and you are so worried you want to elope?

And...how likely is it that people will act out? Do they do this on a regular basis, or are you worried that the wedding will be a trigger for unacceptable behavior? Are there certain people who can't be trusted to behave? You may want to consider not inviting those people.

Why not elope then have a reception with her side of the family, using the money she's given to pay for it? If she's desperate to be there for the elopement, consider having just her and someone from your FH's side?

My in-laws hate each other. When I say hate, I mean hate. Without going into too many revealing details because this is a public forum, MIL and FIL divorced due to an affair MIL had with someone very close to FIL (and she is still with this person). This ripped the entire family apart and it has never recovered. FIL's side hates every single person on MIL's side, MIL's side hates every single person on FIL's side. We've fielded phone calls of them screaming profanities at each other. FIL and MIL's SO have gotten into fist fights at Christmas dinners where everyone was present, and also in a hospice ward right over someone's death bed. I'm talking full-on throwing each other into walls and knocking out veneers kind of fighting.

Needless to say, they are an absolute field of landmines.

I stressed for a long time about how to handle this at the wedding - where to seat them, will they fight, what do we do if they fight? Am I going to be dealing with FIL and MIL's SO throwing each other over the ceremony chairs? We had a small, family-only wedding, and I finally decided to just let them handle themselves.

It turned out just fine. While the families separated themselves on their own (they chose separate tables at the reception, and separate rows at the ceremony), everyone was not only well-behaved, but amicable. They didn't make it awkward, either. They were nice to each other, they made small talk during the cocktail hour, and they took pictures with us together like normal, rational people (FIL and MIL even stood next to each other in the portrait with my parents, and MIL's SO elected to sit out all family portraits to keep the peace).

While there are always exceptions and people who just can't handle themselves, I think most families - especially parents - will keep themselves in line for a loved one's wedding.

If the only reason you want to elope is that you are worried your family will make it awkward otherwise, I would just talk to them. Explain that you want them to be present, but that you are expecting civility at a bare minimum.