You know, after I posted my initial query above I went back over the individuals in question and like you now think that my previous detective work was not watertight.
Before I continue, thank you so much for your reply. It is much appreciated.
Can you confirm from other records (censuses, marriage/death) that the family with Elena/Alfonso emigrating in 1915 is the right Carmela? On Ellis Island this family does not appear to be from Cerreto Sannita, and there is another Carmela aged 15 arriving in 1915 with different relatives who is from Cerreto Sannita.
Carmela #1I see Carmela (age 12 mos) immigrating 18 Sep 1901 with Luise Maria Lucia (29) with arrival destination as Paterson NJ to relative husband Ant Guarino at 113 Reed St.
In October 1915 I think this is the same Carmela, another passenger list with Ma Concetta Di Luise (38) step?-daughter Carmela Guarino (15) both born Cerreto Sannita, and children Crestina Guarino (13) Antonio Guarino (9) Antonetta Guarino (5) and Luciano Guarino (4) all US born. Departure relative "Mother of Luisa Crestina, Cerreto Sannita" and arrival destination of Middeltown CT to relative Antonio Guarino at 88 Liberty St.
Carmela #2In May 1915 I see this as a different Carmela - Maria Antonia Iandolo (53) with children Carmelo Guarino (16) Elena Guarino (14) and Alfonso Guarino (9). Destination is her daughter in Brookyln NY.
I am leaning toward the first Carmela being mine as I know the family settled in CT, and she married in Waterbury to Frank in 1920. If true this is an exciting development as I potentially have her father's name and a new lead to follow.
For example, this may be Francesco/Frank in 1910:
https://familysearch.org/pal:/MM9.1.1/MK2G-N82
cousin Peter Barbieri, possible brother Louis
Thank you so much - this looks very promising. I'll have to look more into this and see what I can learn from the other relatives this Frank is living with.