Kim Cattrall had a reason to celebrate on Sunday as she marked Mother's Day in the UK.MORE: Kim Cattrall announces amazing new role after turning down Sex and the CityThe former Sex and the City star took to Instagram to pay a heartfelt tribute to her mom Gladys.The Samantha Jones actress posted footage of her mother singing while sitting in an armchair, and revealed in the caption that she couldn't remember what the song was, so would appreciate if anyone knew.VIDEO: Kim Cattrall talks turning down Sex and the City role"Happy UK Mother’s Day! Our Mum serenading us. Does anyone recognize the jingle Mum is singing? She couldn’t remember.