United Kingdom, May 11 -- Mandy Moore considers motherhood to be the "single greatest gift of [her] life".

The 41-year-old actress has taken to social media to celebrate Mother's Day in the US (11.05.25), and to reflect on her own experience of parenthood.

The 'This Is Us' star - who has August Harrison, four, Oscar Bennett, two, and Louise Everett, seven months, with her husband Taylor Goldsmith - wrote on Instagram: "Happy Mother's Day to all the moms and mother figures in our lives, including my own mama who juggled 3 kids effortlessly (HOW!??). Being a mom is the single greatest gift of my life and while you're never off the clock worrying or stressing or planning, the quiet, unmistakable joy triumphs over everything else. I'm endle...