Yes, the plural form of the proper noun Rivers is Riverses.
example: The Riverses are my neighbors.
Note: A name is a proper noun. A proper noun is always capitalized.
If the singular family name is Korniotis, the correct possessive form is the Korniotis's family estate.The plural name would be Korniotises; the plural possessive Korniotises'.If the singular family name is Kornioti, the correct possessive form is the Kornioti's family estate.The plural name would be Korniotis; the plural possessive Korniotis'.
The plural form of a family name ending in "N" typically adds "s" or "es" depending on the specific name. For example, if the family name is Johnson, the plural would be Johnsons. If the family name is Cohen, the plural would be Cohens.
Silvises
The plural noun 'families' is a word for two or more groups of related people.For example:My family has just one car. (singular)Most of the families in my neighborhood have two or more. (plural)
You would say the Alvarez family or the Alvarezes.
The plural of Lewis is Lewises. (Surnames ending in S usually add -es.)
There is no plural noun. The two nouns in the sentnece are life and family. The word family is a singular noun, the plural form is families. The word life is a singular noun, the plural form is lives. Actually, using either or both plurals (lives, families) would not change the meaning of the sentence.
You would just say the Velasquez family.
The James family are the Jameses.
The plural for the name Huggins would be Hugginses. The Huggins family lives on my street. One of the Hugginses is my brother-in-law.
Forresters is plural for the members of the family.
The plural of the surname would be Whitbys. Where it might not be clear that the name is Whitby, not Whitbys, use "Whitby family" instead.