What is Aunt Juliana's importance within the context of the play and importance in the establishment of Tesman and Hedda?
Very interesting question. What I like about it is that it seeks to explore the role and purpose of minor characters in relation to the whole work - something that we often forget. Juliana Tesman is George Tesman's aunt, who has never married. The two share a deep affection for each other. In fact, for George Tesman, his aunt assumes a parental role, as he calls her "father and mother in one" for him.
We also know that Juliana is devoted to her sister, Rina, who is an invalid. She cares for her and obviously finds meaning in her work of nursing invalids. When Rina dies, for example, she immediately wants to bring in another invalid border who she might look after. She is a wonderful nurse and part of her identity is caring selflessly for others. This willingness to sacrifice herself and find meaning in duty and responsibility means that in the play she acts as a foil for Hedda, who we know detests her and can't understand how anyone can find meaning in service to others and fulfilling their familial duty. Aunt Juliana is also constantly hinting that Tesman and Hedda should have a baby. She is well meaning, and tries to get on with Hedda, but their friendship is hindered by their different class backgrounds and Hedda's hatred of Juliana.