If you are planning a vanity in a space like this (I am guessing about 48” wide), I have a couple of thoughts to share.
If two people will be using the space, you can’t use it at the same time because of the narrow width of the space. Separate storage drawers for each person is better than this particular vanity arrangement with plumbing for two sinks taking up most of the cabinet space.
One nice (rectangular?) single sink in the center would allow for a bank of drawers on each side. A center cabinet @24” wide or enough space for the sink would allow two 12” drawer units for each person’s personal stuff. I would want four or five drawers per person. Things like a hair dryer and clean towels can be stored under the sink if there is no additional storage in the bathroom. Each person could have a hand towel holder mounted on their side wall. A wall-to-wall mirror above the sink will make the space feel bigger. You could have two narrow recessed mirrored medicine cabinets to the right and left and a plain mirror centered over the sink.
I would provide a double GFI outlet for each person.