More than a decade ago Chris Noonan wrote and directed “Babe,” one of the most enchanting of all family films. Now, having been out of the spotlight since then—a hiatus of late Kubrickian proportion—he returns with this mildly pleasant but ultimately rather tepid biopic of the Victorian-era author of the “Peter Rabbit” books. “Miss Potter” is amiable but, despite a vaguely feminist stance and a narrative turn in favor of environmental consciousness toward the close (not unlike “Happy Feet”), a mite too weightless to be much more than nebulously nice.

Richard Maltby, Jr.’s script centers on the very beginning of the author’s professional career in the early 1900s. Beatrix (Renee Zellweger) is presented as a slightly ugly-duckling type who’s always been an imaginative storyteller and is devoted to her drawings of personable animals in pretty pastels. Her artistic proclivities have been persistently supported by her genial father (Bill Paterson), but the likelihood that she’s turning into a spinster distresses her mother (Barbara Flynn), a determined social climber very conscious of appearances, who has assigned her a dour gray-haired chaperone (Matyelok Gibbs) to assure her name is never besmirched.

Beatrix is unimpressed by any suitor and remains determined to see her peculiar beast fables published, despite the fact that no firm expresses any interest in them. One story is accepted, however, by the Warne Press, whose two operators decide to fob the project off on their younger brother Norman (Ewan McGregor), who’s been demanding to join the company, merely as a way of placating him. Norman proves as anxious to do the book right as Beatrix is to have it properly realized, and their joint commitment results not only in an impeccable little volume but—to everyone’s astonishment—an instant best seller that becomes the first of many. And, of course, working together engenders one of those veddy British romances between Potter and Warne—you know, one marked by much dithering on the part of the woman and clumsy courtship on the part of the man, with the elderly chaperone humorously outmaneuvered while the lady’s mother frets over the fact that it would make an unequal match (Norman being a common tradesman and all).

Happily, Warne’s gregarious proto-feminist sister Millie (Emily Watson), takes a quick shine to Beatrix and not only becomes her best—indeed, only—friend but encourages her to say yes when Norman finally proposes. But misfortune falls when Beatrix strikes a deal with her concerned parents, agreeing to postpone the nuptials over a summer to test the truth of her love; and in the interval tragedy occurs. That leads to a rather anticlimactic final act, in which Potter moves to a rural area where her fortune allows her to become an early land preservationist against the encroachments of developers and speculators.

As written by Maltby, this is a likable if rather bland biographical story, which Noonan treats with a curious placidity that leaves it feeling oddly limp; the only special effort to spruce it up comes from animated sequences in which Potter’s characters briefly come to life on the page to interact with her—but though spiffily done, these are kept to a minimum (probably a good idea, as their overuse could have seemed arch). But at least the director refrains from dousing things in sentiment, as other helmers might well have done. The cast generally works well for him, though unfortunately its major element—Zellweger—is the weakest link. Her accent is fine, and her plainness suits the part, but she never manages to generate the warmth that would make us identify with the character. (Lucy Boynton, who plays Beatrix as a young girl in the early going, actually strikes a more persuasive note.) On the other hand, MacGregor is a model of befuddled charm, Watson is very winning (even if Millie seems an anachronistically modern character), Paterson and Flynn are just about perfect for their roles, and Gibbs proves a wonderful scene-stealer. The film is beautifully made, with creamy cinematography by Andrew Dunn that complements Martin Childs’s colorful production design, Mark Raggett’s art direction, Tina Jones’s elaborate sets and Anthony Powell’s lovely costumes. And the score by Nigel Westlake and Rachel Portman serves the mood without being particularly imaginative.

But in the end “Miss Potter” is rather like its subject’s books—pretty to look at, sweet without being syrupy and cute without being cloying, but rather thin.