It's easy to see Stella McCartney's progress through the seasons in terms of a young woman's life stages. First, there was the student, picking her way through market stalls in search of vintage lingerie and old men's tailoring. Then came the club years, up dancing all night. Next, whoa: love, marriage, a baby carriage—and before you know it, back to work, a changed person.

Her collection notes, channeling words like "easy," "relaxed," and "inner confidence," certainly seemed to reflect a new state of grown-up serenity. Judging by the clothes she showed here, it involves thinking about the need for a sporty pantsuit—a go-to-work brass-buttoned blazer and a smart pair of pants. Oh, and let's see, a breezy oversize shirtdress to pull on double-quick with a pair of heels, and out the door. Plus, something simple, like a sharp-chic bustier dress, to jump into while feeding the baby—and on to dinner.

As all the above made clear, McCartney's come a long way in thinking through what her clothes are meant to do for her peer group. Her choice of color and print caught the general season's drift of whites, pale blues and grays, and art-based patterns (in her case, inspired by Jeff Koons), but she wasn't stressing over being über trendy. What she's doing now doesn't make the headline-grabbing class of directional fashion, but maybe that's a conscious decision. Like all young moms, she's reached the point where the woman separates from the girl.