It was Mother's Day in America yesterday, and stars took the time to honour their mums and cherish some of the special memories they've shared together. Celebrities such as Michelle Obama, Madonna, and Meghan Markle — who is celebrating her first Mother's Day since giving birth to baby Archie — posted touching messages for the special holiday, and our hearts feel full just reading them. "Mom, thank you for kindling that fire within me, and for your example as a mother and a grandmother to our girls. We would never be who we are today without you," Michelle Obama wrote in an Instagram post. Check out how even more stars paid tribute to mothers ahead!