(Warning: huge spoilers for Riverdale ahead. Read at your own risk, fans!)
With all the mystery surrounding Betty's (Lili Reinhart) long-absent sister Polly (Tiera Skovbye), it makes perfect sense that the Coopers' declaration of Polly's mental instability wasn't the only thing keeping her in that group home. It turns out that fans were right to be suspicious of the Coopers' motives for keeping Polly hidden... and no, it's not because Polly is just one of Betty's secret split personalities. New photos and clips reveal that Polly is pregnant.
Behind-the-scenes photos from YVR Shoots reveal the Cooper family out for a snowy stroll with Betty and Jughead (Cole Sprouse) arm-in-arm. (Are those Bughead shippers on the right track?!?) The most noticeable thing about the scene, however, is that Skovbye is holding her belly.
While that's not confirmation of Polly's pregnancy, a scene released on YouTube is: a video watermarked with @UpdateRiverdale also reveals a scene in which Polly, Betty, and Veronica (Camila Mendes) discuss Polly making Betty her baby's godmother. (You can watch the clip over on YouTube.) Note that The CW has yet to release these clips officially.
It's not surprising that Alice (Mädchen Amick) and Hal Cooper (Lochlyn Munro) would keep Polly's condition under wraps. The Riverdale Register journalists absolutely loathed Polly's boyfriend Jason Blossom (Trevor Stines) because of a "maple syrup blood feud" that left a Cooper patriarch dead. There was no love lost between the Coopers and the Blossoms, but perhaps the relationship between Polly and Jason was closer than we initially assumed.
While these spoilers may have ruined the surprise of meeting a full-on pregnant Polly, the show has actually dropped a ton of clues about Polly and Jason having a baby. Jason selling drugs makes a lot more sense: perhaps he needed money in order to support his child. It also explains why Jason's grandmother told Betty that Polly and Jason were engaged — perhaps Jason proposed when he learned Polly was having his kid.
While Hal made it seem like Polly tried to kill herself over something that Jason did to her (which could still be true, we don't know yet) it's far more likely that Polly was sent away for as long as she was because her family discovered she was pregnant. Could this reveal about Polly also explain why Jason wanted to run away from home? Maybe Polly was sent away because her family worried that she would try to run off with her much-detested boyfriend.
This spoiler is a juicy one, but while it provides some answers about Polly, it also opens up a ton of questions.