Hehe... that child isn't human. She's a robot. An an-dro-id.
Literal
Hehe... that child, human [not-じゃないの]. Robot [copula-なのよ]. A-n-d-r-o-i-d.
The spelled-out ア・ン・ド・ロ・イ・ド with interpuncts (・) between each character creates dramatic emphasis — revealing the twist one syllable at a time. 人間じゃないの and ロボットなのよ use feminine explanatory forms. The scene has a sci-fi reveal quality.