Basic Trope: A scientist who gets emotionally attached to the subject(s) of a Mad Science Experiment.
Straight: Alice was hired by Dr. Psycho to take care of the children who are his research subjects. Eventually, she realizes his plans and ends up rescuing the kids, possibly invoking Mama Bear to Dr. Psycho's detriment.
Exaggerated: Interpreted by Julie Andrews, Alice enters Dr. Psycho's lab, encountering a new family and adventure in Disney's latest Musical comedy.
Downplayed: Alice only looks after the research subjects while Dr. Psycho is out.
Alice is nice to the kids because they remind her of her lost child (or the child she had always wanted, but never had.)
Alice is involved in a project that has created sentient artificial life. They are her children, in a very real sense.
The children are Dr. Psycho's offspring, and Alice is the research subject:
A) She was a Robot Mom created by Dr. Psycho, who created her as a Replacement Goldfish for his deceased wife (the mother of his children).
B) Or perhaps her dying memories were stored inside the A.I. of her robotic body.
C) Or she unwittingly became part of a social experiment made to enforce preventive measures against children experimentation.
Alice treats the kids well and they love her, but she's been secretly working with Dr. Psycho and doesn't care about the kids.
Alternatively: Alice is the Mad Scientist. She's the one who's been controlling poor old Dr. Psycho all along.
Alice never was a scientist in the first place - it is later revealed that she's an agent who is gathering evidence of the atrocities and planing an extraction; she was never involved with experiments.
Alice did experiments with the kids, but actually took care that all the experiments were reversible and painless. And she's doing the research to save the kids who went comatose in another experiment she was forced to participate in.
Alice felt a Cuteness Proximity towards the test subject, an animal so cute that Alice gets overly jealous whenever any other scientist approaches. Comedy ensues.
Alternatively: Alice feels so motherly towards the little alien animal that she fails to react when the animal is about to eat her.
Zig Zagged: Alice is secretly a mad scientist that hates the kids and wants to torture them - but that's because she was treated horribly by the children in another facility, which happened because a more evil mad scientist had manipulated the children so that Alice would be easier to manipulate in this experiment. That is, of course, until Alice finds out and finds evidence showing that that one kid who had treated her horribly, had been replaced by an Evil Twin while the really nice kid is still held prisoner in another facility... but it turns out that Alice actually had her brain stored in a jar and that the kidnapped kid is her grown-up biological son who is hacking into the system to rescue her from the Virtual Reality experiment she's being trapped in.
Averted: Alice doesn't play nice with the kids or pretend to care about them.
Enforced: "This story is too cruel about all those kids being secretly experimented with. Let's give them a mom so they can be happier."
Lampshaded: (After managing to calm down one of the experiments): "That was amazing, Alice. Mary Poppins would be proud."
Invoked: All female scientists in Science Academy are given children psychology and ethics lessons.
Exploited: Alice was hired specifically for her nurturing tendencies, to keep the kids quiet.
Defied: Alice quits after the first two weeks of working with the children - she decides to work as a secretary instead.
Discussed: "These kids are a terrible mess to test with. Why don't we hire a female assistant to take care of them?"
Dr. Psycho realizes that Alice is getting too nosy into his work. She might suspect something. So he plans to make her have an "unfortunate accident".
Or perhaps he could act sensibly, rather than dramatic for the sake of drama, and simply fire her.
Alternatively, Alice is dangerously protective of "her" children... Even if it becomes clear that they present a threat to the world at large.
Reconstructed: Alice is no ordinary scientist. When she's being taken to the basement, she reveals that she knows Kung Fu. After she's defeated Dr. Psycho, the SWAT team comes in and rescues the kids, then arrests Dr. Psycho.
Played for Laughs: Alice goes with Dr. Psycho because she made a bet with Bob that she would be a wonderful assistant for Dr. Psycho. However, Dr. Psycho turns out to be a prankster hired by Punk'd on Bob's behalf and one of the kids is an expert with pranking his mentors.