The pregnant actress says the Tree of Life pendant "reminds me so much of the roses I made out of ribbons for my friends and family while in the hospital".
The duo's necklace is available in silver, gold and rose gold with prices ranging from $198 to $998.
Net proceeds will benefit Christina's foundation Right Action for Women. The foundation "encourages women to learn facts and figures about breast cancer and provides funding for the expensive MRI screenings that help in early detection of breast cancer".
[Image via Adriana M. Barraza/WENN.]