While she’s never quite descended to “whatever happened to…” levels of invisibility, it’s certainly been a quiet couple of years for Emily Watson. The London-born actress’s film career started relatively late, but with a bang all the same: in 1997, aged 30, she landed an Oscar nod for her stunning big-screen debut in Lars von Trier’s “Breaking the Waves” (still one of the Best Actress category’s prouder moments), and swiftly followed it up with a second for “Hilary and Jackie.”

While never regaining that level of individual attention, she kept the momentum going through the early 2000s with high-profile roles in “Gosford Park” and “Punch-Drunk Love,” but things dried up considerably from there — tasty appearances in the ensembles of “The Proposition” and “Synecdoche, New York” were only partial compensation for the indignity of having to simper through the likes of “Miss Potter” and “The Water Horse.” (An apparently weighty lead role in Marleen Gorris’s admittedly iffy-looking “Within the Whirlwind,” meanwhile, got lost in a distribution vortex of its own.)

Now in her mid-forties, with the mixed blessing of an unconventional movie star’s face, Watson seemed to have joined the large club of middle-aged actresses with brighter futures on stage and the small screen. Or perhaps not, as this year marks something of a revival in her big-screen fortunes. It remains to be seen how much she’s been given to do in Steven Spielberg’s “War Horse,” but it’ll certainly be more widely seen than “The Water Horse” — or anything else she’s done in her career, for that matter. Next year, meanwhile, she’ll be seen in Joe Wright’s starry new adaptation of “Anna Karenina.”

None of this is as heartening for the fans, however, as her first lead role in several years — as heroic social worker Margaret Humphreys in Jim Loach’s true-life drama “Oranges and Sunshine.” I saw the film on its UK release way back in March and suggested then that Watson’s sincerely committed performance could benefit from an Oscar campaign by an enterprising US distributor. 

The film was duly picked up by new indie outfit Cohen Media Group — now, with the film’s US release a month away, and the Best Actress race still highly malleable, the buzz is indeed beginning to build. CMG scored one Oscar nod in their first year of business (Best Foreign Language Film for “Outside the Law”), and they seem bullish about cracking one of the larger categories this year. At Toronto, they picked up Luc Besson’s “The Lady,” which some pundits seem to think could be a Best Actress play for star Michelle Yeoh. Given that film’s so-so responses, however, they might be better off concentrating their efforts on a third nomination for Watson.

It’s been too long since I saw “Oranges and Sunshine” to attempt writing a formal review, but the film is a solid, impassioned, only slightly stodgy bit of truth-pursuit drama in which the first-time director makes no secret of the fact that he’s Ken Loach’s son — he cut his teeth on assorted British TV soaps, but shares his dad’s stylistic pragmatism and earnest foregrounding of the social issues at hand.

It’s an approach that serves his moving narrative well: the British-Australian co-production tells the shocking, little-covered story of the “home children” scheme initiated by the British government in the 1950s, whereby many UK children from poverty-stricken families were deported to Australia. Promised bright new lives (the “oranges and sunshine” of the title), the hapless kids were instead institutionalized or put to work in labor camps — with their original families kept wholly uninformed as to their whereabouts.

Watson plays Humphreys, the woman who worked doggedly to uncover the scandal and bring it to public attention, reuniting many a scattered family along the way. It’s a role that perhaps sounds more epically awards-baiting on paper than it does in practice, partly because Rona Munro’s slightly pat script is content to define the woman more by her noble actions than her inner passions — and partly because Watson approaches it with her customary intelligent dignity rather than any sense of shrill movie-of-the-week self-regard.

There’s an innate honesty about Watson as an actress that the role flatters, even as it denies her the emotional complexities of her early-career highlights — truth be told, an excellent Hugo Weaving has richer dramatic material to work with as one of the “home child” victims whose life and family Humphreys helps rebuild. But UK reviews focused principally on Watson’s thoughtful work in a welcome comeback role of sorts, and I expect US ones will follow their lead.

I suspect many in the Academy’s actors’ branch would respond warmly to the old-fashioned virtues of Loach’s straightforward, heart-driven film — the challenge for Cohen Media Group will be bringing it to their attention amid the glut of higher-profile autumn prestige work. (Happily for them, it’ll play very well on DVD.) The Best Actress category feels very much in flux at the moment: Harvey Weinstein’s two big guns (Michelle Williams’s Marilyn Monroe and Meryl Streep’s Maggie Thatcher) have yet to be seen, while sight-unseen frontrunner Glenn Close came a little unstuck with the mixed reviews for “Albert Nobbs.”

This, then, is a good time for the category’s many indie outliers to make their presence felt in the conversation. A number of them are British: Watson, Tilda Swinton (“We Need to Talk About Kevin”), Olivia Colman (“Tyrannosaur”) and Rachel Weisz (“The Deep Blue Sea”) make up a quartet of UK actresses relying on strong critical buzz to bring their tiny vehicles to awards voters’ attention.

At least one of them, I sense, will break through — and while Watson’s is arguably the least arresting of those performances, it comes packaged in the most broadly palatable film. (Furthermore, Spielberg’s upcoming epic will keep her face fresh in people’s minds.) Whatever the outcome, it’s nice to have her name back in the mix.