Seen plenty of them....
they have the same leg structure that the regular queen does, but her butt is smaller and to me it looks triangular almost, big waist tapering to a pointy butt.
They will be in any part of the hive, they move fast, they DON"T have the nice ring of attendants. So very few of the regular queen finding cues. They will be very very difficult to find one if you are looking for one.
Another week or so and check for eggs. If you are worried you can keep adding frames of eggs from a different hive, if there is not a queen in the hive they will try to raise another.