Where should you place the apostrophe in the sentence Mrs Washington had misplaced her sons new address and phone number?

If Mrs Washington has only one son with a new address and phone number, then:Mrs Washington had misplaced her son's new address and phone number.

Between the son and s.

Now If Mrs Washington has two or more sons each with a new address and phone number, then:Mrs Washington had misplaced her sons' new addresses and phone numbers. After the sons, and add the es to address and s to phone number.

or:

Mrs Washington had misplaced each one of her sons' new address and phone number.

Again after the sons.