Anna was Akino's trainee at Aria company before Alicia showed up, and it's very likely was a Prima before Alicia was even taken on as a trainee. She later met Albert, a fisherman from Neo-Burano island, whom she married and had a child with.

It was most likely due to the pregnancy and marriage that she left her position as an Undine and went on to help the women at Neo-Burano island to make lace patterns. She later had her son, Ahito.

In episode 7 of Aria the Origination, Akari and Alicia (along with President Aria) visits Anna on Neo-Burano, and, together with Akino, they all spend the evening reminiscing about their lives and about Aria company.

Anna is an anime only character, and does not show up in the manga.