What is the width of the space for the vanity pictured in the floorplan?

looks like 4 feet or a little bit more have to check on exact numbers

This might work:

1. Put the toilet where the vanity is currently. You'll be able to see the toilet when the bathroom door is open. So, you have to decide if that will bother you.
2. Keep the shower in its current location.
3. Place his and hers vanities on the left and right of the shower. 15" deep vanities will give you 42" clearance between the two vanities. That's a little cozy when both vanities are in use. It depends on why you want the double vanity. Some of my clients want a double vanity just so that each partner can have their own, separate space.
4. Fixed glass on the left and right of shower with door centered.

Why??? You do not have enough space. How much time does anyone need to spend in front of a sink? It will look terribly cramped if you tried to put two sinks in there.

If you need a vanity with a mirror for putting on make-up, consider putting it somewhere else than the bathroom. I've always put make-up vanities in the bedroom.

You could try putting a little bit larger sink in the vanity, that will cut down on counter space, but allow 2 people to brush their teeth more comfortably at the same time. I never see the need for 2 sinks, really. I don't spend time with others in the bathroom when I shower, etc.