The sister is arrested on day 21 for an unknown reason. It is possible to adopt the niece on that date, but it will cost 40 credits. She will be added to the number of family members the inspector has to care for, but the day after she is adopted, she will bring her mother's savings with her, which will add 100 credits to the inspector's available cash. If the niece is not adopted, at the end of the next day, the inspector is informed that she has disappeared.
Netting an immediate profit of 60 credits, but increasing the food costs for the family by 5 per day, she will yield a profit of 15 credits if kept alive until the end of story mode. However, if fleeing the country for Obristan (endings 16 and 18), she will end up costing more money through the need for an Obristan passport of her own.
If adopted, the niece can get sick if without food for 2 days or if without heat for 3. Her sickness threshold is 4. Just like everyone but the inspector, she gets hungry, sick, cold, very sick, and possibly dies.