Barton explains, "She is going to have the most fabulously dressed baby, I am sure, because she is so stylish herself."
The Rolling Stones and AC/DC logo T-shirts were impulse buys for Barton. "They were so unique," she said. "I just loved them!"
Richie, 26, is due when January, with her first child with boyfriend Joel Madden – and Barton had to shop not knowing the baby's gender.
"She actually doesn't know what she is having," says Barton. "She wants it to be a surprise."