2 תשובות
"my" is a possessive pronoun used only as an adjective before a noun.

ex. 1: "my sweater keeps me warm in winter."

"mine" is the possessive case (or "genative") of the pronoun "i" and is only used as a direct object (or predicate nominative).

ex. 2: "that sweater looks like mine."
ex. 3: "that toy is mine."

in standard english, we always refer to other people before mentioning ourselves: "sally & i went to the store" or "she gave the book to sally and me."

that's why anna should come first, not "mine."

correct sentence: "the toy was anna's and mine."
אין כל כך משמעות אחרת אם את כותבת כך או כך... זוהי צורת התבטאות, mine זה יותר בשפה הגבוהה ו my זה יותר בשפת העם (שפה נמוכה, יום יומית)...