According to Bronfenbrenner’s ecological model, a girl’s face-to-face interaction with her siblings would be part of her

mesosystem

Explanation:

Bronfenbrenner's ecological systems theory is a meta-theory focused on a child's development. This theory indicates complex environmental 'layers' that have an effect on a child's development. Bronfenbrenner categorizes a person's environment into five systems: 1-microsystem (i.e., direct contact with the child, e.g., parents and siblings), 2-mesosystem (i.e., interactions between the microsystems in one's life), 3-exosystem (i.e., social structures that indirectly influence child's development), 4-macrosystem (i.e., cultural context), 5-chronosystem (i.e., transitions and shifts that influence development). A mesosystem comprises interactions between the microsystems in which the developing individual participates. In consequence, a girl’s face-to-face interaction with her siblings is part of her mesosystem because siblings form part of her microsystem and they have a direct influence on her development.