sink base cabinet, probably a 36" wide sink base cabinet. I would mock up a sink that is about 32"-33" wide, and indicate the faucets about 14" to 15" apart. Have your girls stand in front of the mock up and see if they feel like they are too close to one another.
reputable kitchen & bath design studio, you should be able to source a vanity just like this. As an example we have a display of this very product in our showroom currently. Senior Designer~Urbana, Victoria BC