Your dream is rich in symbolism and reflects various aspects of your emotional state, relationships, and personal concerns. Let's break down the key elements for interpretation.

First Scene: The Old Woman and the Letters

1. The Old Woman/Therapist: This figure may represent wisdom, guidance, or a part of yourself that seeks understanding. As a therapist figure, she may embody your desire for emotional support or resolution of inner conflicts.
2. The Letters: The letters from your mother and grandmother on pristine paper suggest important messages or unresolved feelings regarding family connections and your past. Their presence in the therapist's inbox signifies a longing for acknowledgment or validation of these feelings.
3. The Receptionist Area: The absence of a receptionist and the setting being after hours might indicate feelings of isolation or waiting for guidance. It suggests you may be navigating these emotions alone, seeking answers that feel out of reach.
4. The Therapist's Worry: Her preoccupation with a letter that negatively affects her work might mirror your own anxieties about communication, acceptance, or self-worth. This could reflect a fear of rejection or unresolved issues in your own life, particularly regarding how you perceive others' opinions of you.

Second Scene: Visiting Your Sister

1. Your Sister’s House: The large house signifies comfort or familiarity but also may highlight feelings of distance or disconnection in your relationship. The winding road can symbolize the journey you take to understand your family dynamics.
2. The Young Girl and the Old Woman: The contrast between youth and age, along with the nurturing aspect of the old woman, may reflect your own nurturing instincts or the desire to care for others. It could also symbolize the cycle of life and the wisdom passed down through generations.
3. Sister's Appearance: Your sister's unexpected weight gain may represent your own insecurities or fears related to body image and societal expectations. Since you mention that your husband is encouraging you to lose weight, this could be a direct reflection of your concerns about body image and pressure from yourself or others.
4. The Question of Town: Your familiarity with the town and your independence in getting there suggests a sense of autonomy and experience, despite feeling overwhelmed by familial expectations or perceptions.

Overall Interpretation: Your dream seems to revolve around themes of family relationships, self-image, and the search for validation. The contrasting elements of care and worry in the first scene, along with the familial dynamics in the second, highlight your desire for connection and understanding, but also your struggles with self-acceptance and the weight of expectations from those around you.

Advice: Consider reflecting on your relationships with your mother, grandmother, and sister. Are there unresolved feelings or conversations that need to take place? Additionally, think about how you perceive yourself versus how others perceive you. It may be beneficial to explore these feelings further, possibly through journaling or talking with someone you trust. Embrace the wisdom from your dream and seek ways to nurture both yourself and your relationships.