Central Theme in a Novel Excerpt

Read the following excerpt from a contemporary novel:

"As she stood at the edge of the pier, the crashing waves mirrored the turmoil inside her. Each wave reminded her of a moment she wished to forget, yet the ocean's vastness seemed to offer a promise of renewal. She thought about her family, the losses they faced, and the strength they could muster to move forward. In that moment, she realized that just as the tide ebbed and flowed, so too did their lives—a cycle of loss and healing."

What is the central theme of this excerpt?