When using plural possessives, do you make the noun afterwards plural?

For example:

Many families own pets which live in their homes.

or

Many families own pets which live in their home.

Since the homes belong to several families, you'll need to use the plural form.

To make the sentence have a plural possessive noun, you would need to say,

"Many families'pets live in their homes."

Then, families' is the plural possessive.

When using plural possessives, the noun that comes after the possessive should remain in its plural form.

In your example, the correct sentence would be:
"Many families own pets which live in their homes."

Here's how to arrive at the answer:
1. Determine the subject of the sentence. In this case, it's "families."
2. Identify the possessive pronoun required. In this case, it's "their" because it refers to multiple families.
3. Determine the noun that the possessive pronoun is referring to. In this case, it's "homes" because it indicates that each family has its own home. Since "homes" is plural, we keep it in its plural form.

Therefore, the sentence should read "Many families own pets which live in their homes."