center the mirror at eye level over the sink.

if you don't have room to mount the sconces on the same wall as the mirror, mount them to the wall. centered yey level. For me generally 65" off the floor.

if you put a light over the mirror, you can still have sconces, just put them on a separate switch.

Would something like this look okay? One double sconce in between?

There isnt another wall to mount an additional sconce. The toilet is next to the vanity

You can do a double sconce in the middle, but make sure you aren't trying to cram everything in these 63 inches.

Maybe look for a mirror that is 20" wide.

So weird - there were no photos in Lyn's comment when I read it. Also, chispa and OP's comments weren't showing when I was drafting my comment! That's why my comment makes me look a bit crazy 😜

It is funny that I grabbed the same photo showing side mounted sconces as Lyn did!

If you don't want to return the mirrors to find ones that would work to allow you to have room for mounting the sconce on the outer side of the mirror (assuming that your vanity is in an alcove):

You could mount a third sconce in between the mirrors if you want depending on the size/shape of the sconce.

You also could just use a double headed sconce in between the two mirrors (this works if your vanity is not in an alcove - unlike the example above):

How tall is the wall behind your vanity? If you have a tall wall, it looks better to have longer mirrors.

You should take the heights of the people (or person) who will be using the mirrors into account when deciding on how far off the floor to install your mirrors. While the general rule is to mount mirrors between 60-65" from the floor, it needs to mounted so that the eye level of the people using them is at the center of the mirror.

I have a cousin who is 6'1" and her husband is 6'7" - she had ceilings that were about 9.5' - so, she purchased longer mirrors + mounted them higher so that the middle of the mirror was at her eye level. This height still worked fine for her husband.

Yep if you use those mirrors there is only room for a sconce between them.

We don't know if there is room for lighting above the mirrors because you don't show that area in any of your photos.

Such a small area for a double vanity. Consider running a mirror from wall to wall.

The mirrors might be too big for the space. Ideally, you have sconces on both the outside of the mirrors and in-between. We can’t see the vanity area and mirrors well enough to tell you what lighting is best. They look very wall as well, so something above them might not look right either.

Can you shoot a photo of the vanity area, including the whole wall, plus the mirrors?

Here is the bathroom before the demo

Am I to understand the vanity is the same vanity?

You can not do what you want.

You removed a very good concept in a space like this, and all you will end with is a gap and small mirrors. Not EVERY vanity on earth is meant for the look of two mirror/sconces, and yours is definitely not: )

I understand you do not want a boring mirror glued to a wall....however? You have a 66" vanity and it is still jammed to a right wall!

Buy a 30" x 60" great framed mirror and put two lights above the new mirror. Ceiling seems 8' is it more? You can have a frame made and a mirror templated and installed inside, to the very inch height you want. But after all

It is what it is: ) and a single sconce in the middle of those mirrors won't get you a good look........and will be awful and unbalanced lighting to boot.

Good advice already - agree the bath is def the place to focus on functional lighting so I would not have just one double sconce that lights only half of a face- I think more mirror is better with double sinks so prefer one larger mirror

If you had a sconce that you wanted to use, you could also pair it with lighted mirrors. They're good for putting on make-up and most of them can different settings to adjust the brightness and coolness/warmth of the light. It does, however, have a more contempory feeling to them, which may not be the look you're going for though.