As Elizabeth didn't marry Mathias until 1663, this Elizabeth b. in 1645 wouldn't be their child, but most likely is Elizabeth Duston b. abt 1645. Unconfirmed sources indicate Elizabeth Duston may have been b. in Haverhill, Ipswich, Kittery, ME and Dover, NH with dates specified as May 3, 1645, abt. 1645, abt 1648 etc.
In checking some of the duplicates in these profiles, there are other 'Button' children - Mary, Thomas, etc. attributed to Elizabeth Duston Button. It appears that their last name Button all relate to the interpretation of the will of John Wheeler, naming Mary, Thomas, and Elizabeth as grandchildren, and interpreted in The Earliest Descendants of Mathias Button, to have been Button children. This is later clarified in the Essex Institute Historical Collection Vol 46. - that the named children were Elizabeth's children by Thomas Duston.
The Essex Inst. further indicates that Mary Button, b. abt 1664 may have been a child of Elizabeth and Mathias Button. This text further indicates that this second Mary Button - may have died young, but is unconfirmed. That interpretation is based on the will of Mathias' son Daniel 1677, estate divided among Mathias four children, and does not mention Mary by name.
I would suspect this woman should be merged with the other duplicate Elizabeth Duston's and probably the same for Mary Button (Button-193) b. 1633 should be Mary Duston; and Thomas (Button-459) should be Thomas Duston.