Like other Roman Empresses from this period, Faustina already had close family ties to the imperial family before she married a man who would become emperor, in her case on her mother’s side. Her father and brother were consuls. Her mother was half-sister to Vibia Sabina and niece to Trajan. Unlike her aunt, she didn’t marry to strengthen her husband’s claim to a place in the succession, though her marriage was almost certainly still political. The match was a good one and the couple cared deeply for her. Antoninus Pius seems to have been mostly (or entirely) monogamous to her. At the very least, he took no official lovers. The couple had four children together, three of whom died before Antoninus became Emperor in 138.
[Denarius depicting "DIVA FAUSTINA," 2nd century CE, source: Wikimedia Commons]
This was not all he did, however. Antoninus was determined to keep the memory of his wife alive. He deified her almost immediately and had a temple built in the forum.*** He had several coins struck showing her as different goddesses. Sculptures of her were brought out for public events for the rest of Antoninus’s reign. Enough of these survived over the centuries, that her image became an ideal not merely for the rest of her husband’s reign, but for centuries afterwards.
*As opposed to becoming the provenance only of her priesthood and a few devoted followers.
**This is significant in large part because there were almost no such programs for women and girls, while there were several for men and boys.
***Once he died it was reconsecrated to both of them rather than just her.
Life of Antoninus Pius, Historia Augusta - Lacus Curtius
Bergmann, Bettina. "The Moon and the Stars: Afterlife of a Roman Empress" - Academia. edu
Burns, Jasper. Great Women of Imperial Rome: Mothers and Wives of the Caesars. New York: Routledge, 2007. [Note: This book can be found on Google Books here.]
Faustina the Elder - Wikipedia