Maggie Simpson is an enemy in all chapters of Eggs for Bart.
Chapter 1[]
Maggie first appears on Night 2, occasionally you will hear her crying upstairs, you will need to run and sooth her to calm her down, failure to do so will result in her jumpscaring you.
Chapter 2[]
Maggie is also a threat in Chapter 2, she only appears in the house and works the same way as in Chapter 1. At the end of Chapter 2 her soul is put to rest as Barney takes the eggs.
Chapter 3[]
In chapter 3, she can be seen in level 1 where her body rests with the other family member's bodies. In the final level, a grid version of Maggie appears, however since you're stuck in the cot, you won't need to run to Maggie to sooth her.