Here are 2 recommendations that are both 36 inches if you want to lean into the rustic look:

1. https://www.amazon.com/dp/B0GJBT2VRY?lv=shuf&channelId=500&plpRedirect=mhFallback&th=1 

2. https://www.amazon.com/dp/B0BBTD3HVR?lv=shuf&channelId=500&plpRedirect=mhFallback&th=1

I like the round mirror but I’d go with a smaller wood frame. This one is from Amazon

Forgot the pics…

Thank you all so much! Great ideas!

If you are keeping the existing light fixture, I would choose the new mirror mainly for moisture durability and proportion rather than trying to make it a feature piece.

For a 36-inch width, a simple frame in sealed wood, brushed metal, or a clean rounded metal profile usually feels safer than anything heavily distressed or very thick. In a bathroom, I would look for a frame finish that is rated for damp conditions, a mirror with a proper safety backing, and hardware that holds the glass slightly off the wall so trapped moisture does not become a long-term problem.

Since you are not changing the lighting, make sure the new frame depth and shape do not cast extra shadows from the existing fixture. A quick painter's-tape mockup on the wall is usually the fastest way to see whether a round mirror, rounded rectangle, or thinner framed rectangle will feel best.