If Teresa's daughter is my daughter's mother, who am I to Teresa?

You = Teresa

Do you see why?

To determine who you are to Teresa, we need to break down the given information. Let's examine the relationships step by step:

1. Your daughter's mother: This refers to you, as you are the mother of your own daughter.

2. Teresa's daughter: According to the question, Teresa has a daughter.

3. Teresa's daughter is your daughter's mother: This means that Teresa's daughter is actually you. So, in other words, you are Teresa's daughter.

Considering the above analysis, you are Teresa's daughter.