The CARROLL and GELLERT families

I am confident that there is unlikely to be any shared DNA in the ancestors of the CARROLLs and the GELLERTs, due to the fact that both branches were relatively recent US immigrants, from different places, so that it is unlikely that these families had unknown intermarriages in the genealogical time period.  Proceeding from that assumption, therefore, segments can be clearly assigned to one side of the family or the other.

My mother Mary's DNA as well as that of all my full siblings has been tested.  Joe Carroll, her brother, has also been tested, as had Jim Gillert*, their cousin.  Mary and Joe's DNA is from either their mother's [the GELLERT's) or their father's [the CARROLL's] side of the family (their sister Pat died in 2002 and her DNA is not available).  Segments which match Jim and also Mary or Joe are GELLERT segments and can be excluded from the CARROLL family.