She named the erratic Californian singer, best known for changing her appearance and dressing quite scantily, in an interview with Harper's Bazaar magazine.
Samantha said she felt the No Doubt star, who founded a Japanese-inspired clothes label, was her alter ego.
She added: "I've always wanted to dye my hair blonde. Every time I see her, I go, God, I wish I looked like that!"
However, she continued to explain her fashion choices were restricted: "I'm a working mum. We have to pay for child care. I don't have huge amounts of spare cash to spend on designer clothing. I think all working mums are a bit like that."
Samantha also admitted her husband does much of the cooking - and revealed his favourite television chef: "He's quite a big Jamie Oliver fan. At the moment, we're into one-pot cooking, where you shove all the vegetables and meat in the pot, stick it in the oven, and two hours later - wow, it's delicious!"