Answer: Observational learning, model
Explanation: Observational learning simply refers to a method of acquiring a skill, behavior or knowledge by watching or observing others perform such behavior or action. In most cases, observational learning requires an individual to observe another person usually a child's parent, siblings, guardian or other people of higher status and systematically learn to emulate or perform. Such behavior. The individual whose behavior or action is engaging learnt or observed is called a model.
In the scenario above, the younger daughter employs the principle of observational learning in watching the older daughter mow the lawn, where the older daughter acts as a model in which the younger emulates.