This is what we found on Wikipedia regarding the Hamnet:

Hamnet Shakespeare (baptised 2 February 1585 – buried 11 August 1596) was the only son of William Shakespeare and Anne Hathaway, and the fraternal twin of Judith Shakespeare. Hamnet died at the age of 11. Some Shakespearean scholars speculate on the relationship between Hamnet and his father's later play Hamlet, as well as on possible connections between Hamnet's death and the writing of King John, Romeo and Juliet, Julius Caesar, and Twelfth Night.

Hamnet found cultural representation in 21st-century works such as Neil Gaiman's comic book The Sandman, the 2018 film All Is True, Maggie O'Farrell's 2020 book Hamnet and its 2025 film adaptation, as well as the comedy drama series Upstart Crow (2016–2020).