Deadline‘s Michael Fleming announced this morning that Kristen Stewart will play the late Diana, Princess of Wales (aka Diana Spencer) in Pablo Larrain‘s Spencer.

Due to roll in early ’21, the Steven Knight-scripted drama will “cover a three-day period in the early ‘90s, when Diana decided her marriage to Prince Charles wasn’t working, and that she needed to veer from a path that would put her in line to one day be queen,” Fleming reported.

Diana’s chosen path, as we all know, turned out to be sporadic and wayward, and was chiefly defined by a series of extra-marital and post-marital affairs (Barry Mannakee, James Hewitt, James Gilbey, Oliver Hoare, Theodore Forstmann, JFK Jr., Bryan Adams, Hasnat Khan). It ended tragically when she and the totally worthless Dodi Fayed died after a high-speed car crash in Paris on 8.31.97.

Right off the top, the Larrain-Knight project is flawed for two reasons.

One, nobody cares about Diana’s decision to bail on her marriage to Prince Charles in ’91 or thereabouts. What they want to see, of course, is a Harold Pinter-esque drama about her tragic, idiotic affair with Fayed with a special focus on (a) the particulars of her last few hours of life, and (b) the worldwide reaction to her death including the funeral and the Elton John performance of “Goodbye, English Rose.”

And two, the 5’5″ Stewart is way too short to inhabit the physical realm of the 5’10” Diana. Diana was seriously statuesque (5’10” in heels = six feet) and nudging the giraffe realm while Stewart — be honest — is smallish. It would be one thing if she stood 5’7″ or 5’8″ but she’s five full inches shorter than the Real McCoy — you might as well call it half a foot.

Plus Stewart doesn’t look anything like Diana in terms of eye shape or facial bone structure. She was a passable Jean Seberg as they shared certain similarities, but even the makeup guy who transformed Charlize Theron into Megan Kelly would be at a loss.

By the way: The 5’10”, 44 year-old Theron would be too old to play the 31 year-old Diana in Larrain’s film, but she could play the 36 year-old Diana in the Dodi Fayed version.

Larrain has twice cast too-short actresses as famous women — the 5’3″ Natalie Portman as the 5′ 7″ Jackie Kennedy (which didn’t work — Portman was simply too runty), and now Stewart as Spencer.

My pet theory is that Larrain, who himself only stands 5’7 1/2″, prefers to cast women who are shorter than himself.