The pronouns and antecedents in these sentences are:
His-Jeff: the pronoun "his" is used to refer that the woman is Jeff's mother.
They-flowers: To avoid the repetition of the word "flowers" the writer replaces it for the pronoun "they" in the second sentence.
Answer:
his, Jeff; they, flowers
Explanation:
These are the pronouns and antecedents that are used in these sentences. A pronoun is a word that takes the place of a noun. On the other hand, an antecedent is the word that the pronoun refers back to. In this case, the pronoun "his" refers to Jeff, as we are referring to Jeff's mother. Moreover, the pronoun "they" refers to flowers, as the flowers were the ones that were very pretty.