These were briefly mentioned in Pathfinder. Decided I'd do a quick writeup.
Before Android emancipation, many Androids were built with bodies that resembled children, but fully developed minds. These Androids were used for purposes such as undercover bodyguards, human interaction, and maintenance crew for narrow areas. Some were even used for subterfuge and wetwork, as their appearance made them beneath suspicion, and most opposition would hesitate to harm them. These patterns are manufactured to this day, either because the foundry that created them continues to produce the same designs it always has, or in areas where android emancipation is not recognized.
A Child Android's ability score adjustments are +2 Dexterity, +2 Charisma and either -2 Strength or -2 Wisdom. Child Androids are one size smaller than normal (minimum small). Additionally, Child Androids nearly always have the Impersonation Matrix alternate trait.