Meryl Streep's daughter is her "guard dog" - taking on responsibility to protect her from fans

So Mamie has taken it upon herself to step in and stop over-zealous fans from bothering the Oscar winner.

Speaking to Time Out London magazine, Mamie said: "I can be kind of a guard dog. Because my mom is gracious and won't be rude. I will be rude for her. If we're in a restaurant , I just want her to be able to eat. After 'Mamma Mia!' it went crazy."

The 32-year-old actress stars alongside Meryl in new movie 'Ricki and the Flash', in which the 66-year-old screen legend plays the lead role as retired rock star Ricki who returns home to build bridges with her children, one of whom is the troubled Julie depicted by Mamie.

Mamie readily admits her mother's career meant she couldn't always be at home for her and her three siblings but she always respected the fact that Meryl had to work and thinks it set a good example to the family.

When asked if she thinks her mother felt guilty about having to work so much, Mamie - whose father is Don Gummer - replied: "I think she did. She couldn't be at every single school play. But the older I get I realise how valuable it was to have a mother who didn't feel like she had missed out. What I saw was a woman who loved what she was doing and needed it."