Help me identify a famous person!

[Asiama]

Today I saw someone and thought "hold on, I know you..." and then I realised, she's a TV actress. Except I don't know her name and can't place what I've seen her in, and it's driving me mad! Can you help me? She looked like a slightly older version of the attached picture, maybe late 40s or 50s, tall and slim.

Please put me out of my misery!

Mad Men!

Christina Hendricks

No not Christina Hendricks, she looks like she could be her mother though and looks like a slightly older version of the picture of Christina in my OP.

ARGH so frustrating!

Julianne Moore?

Siobhan Redmond?

Kate Walsh?

Sally Dexter? Have seen her in B&Q Watford with a horrendously badly behaved child.

Marilu Henner?

Or Susan Sarandon or Marcia Cross?

No none of those 😞 she's a British actress and her hair was above her shoulders.

Helen McRory?

Felicity Kendall?

Kristin Scott Thomas

Anna Chancellor

Jessica Chastain?

Sorry ignore my last message, I got overexcited as I knew who the pic was but just read the post properly Haha!

Anna Friel?

Gina Mckee?

Amanda Burton?

Is she a redhead?

British, American or another nationality?

Rula Lenska?

Emilia Fox?

Helen Mirren?

Polly Walker

Was it the actress who was in the third (I think) series of Luther as his love interest? I can't think of her name but remember she looks like Christina Hendricks

Calista Flockhart?