Determining name for family relationship that involves a step daughter? [duplicate]

Question

My grandma had 3 kids. Her daughter Sally is my Aunt. She has a step daughter. Her step daughter has a daughter. My Aunt Sally is her Grandmother. What does that make us?

Answer 1

I just fed your information into the Steve Morse's Relationship Calculator in this order:

1. parent
2. sister
3. husband
4. daughter
5. daughter

and it returned that your parent's sister's husband's daughter's daughter is to you a

??? (non-blood relative)

If you ignore the "husband" that led to the step then you get (as @TomH said)

1st cousin once removed (blood relative)

If you really want a label for the non-blood relationship between you, then I think the following would be as good as any:

step 1st cousins once removed

Answer 2

Well ignoring the "step" aspect you would be first cousins once removed. See How to determine relationship with a cousin? for details of how to calculate cousin relationships.