I have Almira Whipple (my 3rd ggm), born in 1805 in RI as Nathan Gove's wife. Her Parents were John Whipple and Sophia Potter, also of RI. This was from "The Gove Book". There is no mention of any siblings of Almira in the book.
I have John's father as Joseph married to Katherine Green. My notes say that this was found at the Vital records of RI from 1636 to 1850, Vol. 1, page 57 at Haverhill Library.
It appears to me that Susan was a sibling of Almira.
Hope this helps.