Anonymous her mother or his mother his son or her son "His" and "her" are possessive adjectives/pronouns. If you used these expressions in complete sentences, the difference would become obvious. There is a second, unnamed person involved in each of your examples.
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Anonymousher mother or his mother
his son or her son"His" and "her" are possessive adjectives/pronouns. If you used these expressions in complete sentences, the difference would become obvious.