Are the androids human DBZ?
So Androids in DBZ are actually better characterized as cyborgs, which are human beings enhanced with mechanical parts to increase their strength and such. So technically, she is still a human, just mechanically enhanced, thus giving her the ability to have children.
Is Android 21 Gero’s wife?
Android 21 is Gero’s wife, she was human just like 17 and 18, but then Gero’s computer infused her with DNA of strong fighters. So she’s like a mix of 17/18’s Human with technological upgrades, and Cell with biological upgrades.