Closely or distantly related?

In the post titled Barbara, Michigan, USA I revealed an acquaintance with a possible close cousin through a common ancestral link. This followed a problem I had recapped in its previous post, Continuing the Journey.... Let me re-explain this and discuss a newly formed problem here.

So, in the recap I had listed the following collection of evidence:

1		BONE	1836	Décès	BARBARA	ANTONINA
2		BONE	1836	Décès	BARBARA	ANDRE
3		BONE	1837	Naissance	BARBARA	TONY
4		BONE	1838	Naissance	BARBARA	ANTONIO
5		BONE	1839	Décès	BARBARA	GUISEPPE

DEATH OF ANTONINA BARBARA (His sister)
Date: 19 Aug 1836
Place: Bone, ALGERIA
Age: 4 years
Father: BARBARA Giuseppe, 40 years old
Mother: BARBARA Rosa, 32 years old

BIRTH OF TONY BARBARA (His brother)
Date: 11 Feb 1837
Place: Bone, ALGERIA
Father: Giuseppe BARBARA , aged 42 years, native of Malta, fisherman
Mother: Rosa VELLA, aged 32 years, native of Malta

BIRTH OF ANTONIO BARBARA (His son, my GGGGrandpa)
Date: 22 Jan 1838
Place: Bone, ALGERIA
Father: Giuseppe BARBARA , aged 44 years, native of Malta, daily worker
Mother: Rosa VELLA, aged 36 years, native of Malta

DEATH OF GIUSEPPE BARBARA (My GGGGGrandpa)
Date: 14 Nov 1839
Place: Bone, ALGERIA
Age: 50 years
Description: Catholic, born in Malta
Parents: BARBARA Antonio and Catarina

PASSPORT APPLICATION
Date: 1835
Applicants: ROSA BARBARA and her daughter ANTONINA

Up till here is the only direct links I have to the family that left for Bona, Algeria.
Now in tracing their point of origin, we' re looking for the marriage of a Joseph BARBARA to a Rosa Vella.

In the birth and notary records at Geneanum there is only one such marriage:

MARRIAGE OF GIUSEPPE BARBARA TO ROSA VELLA
Date: 13 Jun 1820
Place: Zejtun, MALTA
Groom: Josepho BARBARA
Bride: Rosa VELLA
Groom parents: Antonij BARBARA & Rosa GRIXTI
Bride parents: late Josephi VELLA and Maria ZAMMIT

With the subsequent birth of the bride:
BIRTH OF ROSA VELLA
Date:7 Dec 1804
Place: Zejtun, MALTA
Father: Josephi VELLA
Mother: Maria

The problem that this leaves is that the mother of the groom Joseph Barbara does not co-incide with the name of the mother of the deceased Joseph Barbara.

The Barbaras from Michigan provide a couple with the names Antonio Barbara and Caterina, which would match with the parents of the deceased Joseph Barbara, but their marriage is dated as 1815, which would not coincide with the age of 50 years at his death in 1839 and improbable to have borne a daughter, Antonina, in the year 1832 - he would only have been 17 years old. Possible! But hard.

The only proof that can concretize any link is the birth of Antonina Barbara. I have already searched in the Zejtun and Ghaxaq parishes for her birth but to no avail.