After her daughter dies unexpectedly, a toy maker decides to turn her into a robot doll that becomes a serial killer.

This concept might be a little too close to Childs Play (Chucky)

Chucky used magic, and you use robotics, but both are just ways to get past the first 10 pages and into the story about a rampaging serial killer doll.

That doesn’t mean this can’t work, it just needs that one extra thing to set the story apart. like for instance perhaps the doll is actually protecting the father from something.