Angela might have been thinking of the fact that many generations of first-cousin (or closer) marriages in some Moslem cultures have led to catastrophic levels of genetic defects. For example, Pakistanis living in Britain have over half the children born with birth defects in the country.
The solution to the mobs-of-immigrants-on-welfare problem is to eliminate welfare, but it won’t happen unless the voters demand it.
The Amish, however, are outstanding for providing for their own families without government largesse. They also have founded some woodcraft/carpentry industries which specialize in making adaptive toys and furniture for children and adults with various disabilities, this benefiting people far beyond their own communities.