I scanned thru the records for the period right after Matteo's marriage, in case there was a hint, and it looks like his first child (a son) was named Salvatore Antonino Santo.....baptized Nov. 1817. No clue as to who the grandparents were tho.
In March 1820 they baptized a daughter, Anna, and the godparents were Domenico Badalamenti and Anna (no surname) - possibly the grandfather of Matteo?
In January 1823, they baptized a son, Antonino, and the Godparents were Antonino Badalamenti and Anna Badalamenti. (Grandparents?)
In May 1825, they baptized a daughter, Angela. Godparent very difficult to read first name, looks like Domenico Badalamenti
Michel is working on connecting the families and he may be close to the period you're looking for. Maybe he'll be able to find her in the civil records.