My GGransfather may not be my GGrandfather

[tomy]

I have always believed that my GGrandfather was a John McRoberts from Dromore.I have since discovered my Grandfather Alexander McRoberts was born 4/4/1886 at Dromara,he was registered Alexander Kerr after his mother Emma Kerr and on the birth certificate his fathers name was not captured.Although Emma Kerr and John McRoberts eventually had a daughter in 1889 in Ireland and married in Airdrie in 1890 I think John adopted Alexander and was not his real father.I have messaged some of the churches local to the area to see if a baptism or side letter exists but no luck.My question is is it likely that John McRoberts was around Emma in 1885/86 when John was born then they wait 3 years yo gave another child or how could I find out who Alexander's real father could be.

[Kiltaglassan]

I have since discovered my Grandfather Alexander McRoberts was born 4/4/1886 at Dromara,he was registered Alexander Kerr after his mother Emma Kerr and on the birth certificate his fathers name was not captured.

For everyone's information-
Alexander born at Kinallen, Dromore.    #388
https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_returns/births_1886/02606/1962311.pdf
https://www.townlands.ie/down/dromore/kinallen/

KG

[aghadowey]

You really don't know if there was a '3 year wait' for more children. It might be that Emma just didn't get pregnant for 3 years or if there were any miscarriages or stillbirths in between. John could have been Alexander's father but for some reason he and Emma weren't able to marry right away.
Unless you go the DNA route by comparing your DNA with one or more descendants from McRoberts family there's probably no way to know for sure.