Wear what you would have worn if the wedding had been at any other venue. A nice dress, maybe a pearl necklace, flat closed toe shoes.

A halter.

Whatever you would wear to a church wedding. My daughter got married at a farm venue.

Based on the kids clothing choices, I’d say continue to the formal wear like ^^ they said. I’d talk to the kids before purchasing, may be fun for you to shop with the DIL or daughter.

TBH, I like the summer dresses with low boots or flats, look for barn weddings, but they’re pretty common in my area and usually real working barns transformed for a day.

A bridle?

My daughter wore a beautiful white wedding dress, but at her instructions the groom and the best guys all wore khaki shorts and white button down shirts. Rick as all aghast at that! He kept saying how disrespectful it was! I kept telling him it’s what the bride wanted! She wanted everyone to pale next to her beauty!

She had all kinds of cool touches here and there. We just tucked LED lights into the lanterns

Overall venue.

The groom’s mother should wear a knee length halter top skirt covered in rhinestones, and cowboy boots, maybe some Tony Lama ostrich skin boots.

That would be cute! But is the whole wedding theme like, “cowboy”?

Sheepskin.

Anything from a cow would be an udder disaster.

The most expensive jeans and boots you can find.

Wow. Why? What does the cost of something have to do with anything? And the OP has yet to tell us if it’s actually a cowboy theme.

It sounds like they are going for a formal look even if the venue and food are casual. For my son’s wedding on a boat, I was told by DIL to wear a long dress that was purple and luckily happened on a beautiful dress on sale when I wasn’t yet looking.

My first son’s wedding was at the bride’s home on top of a mountain in Vermont. I wore a knee-length pale green chiffon dress with a matching tunic jacket and very low wide heels.

I would ask if they want you and the Mother of the Bride in long or short dresses and then look for something in beige, gold or shell pink that would go with the olive colors. Perhaps a cocktail dress would be a good idea for the range of formality. Comfortable shoes are a must but they could possibly be sandals if you step carefully.

I mean, what does your daughter in law WANT you to wear?

It sounds like you looked lovely @janbb. I wore the same dress at my son’s wedding and at my daughter’s wedding. I loved it on the rack at Goodwill…not so much on me but…it’s was pretty much the nicest thing I had.

^^ Oh yes, as I mentioned above I agree. I would consult your DIL to be and follow her ideas as much as is practical and in accordance with your taste.. Often the Mother of the Bride and Mother of the Groom coordinate colors.

A smile.

Flat bottomed, comfortable shoes. (To avoid the knots and holes in the floor.) And whatever she would wear to a normal wedding.