If you guys ever feel like gambling €4 then I would hazard a guess that this is the death of John Collins.
For the story of Lena to not have really known her father as he died when she was so young then this appears to be the best match based on closeness to 1911, his year of birth, and his place of death.
Again though it would be a gamble !
First name(s) John
Last name Collins
Birth year 1862
Age at death 50
Registered year 1912
Registered quarter/year Oct - Dec 1912
Registration district Cork
Volume 5
Page 86
Tara