It seems so. According to an Entertainment Weekly article, actress Elisha Cuthbert has signed a deal to reprise her role as Kim Bauer. Here's the scoop:
Question: What's the latest on Elisha Cuthbert returning to 24? -- Dominic Ausiello: Ladies and gentleman, we've got a signed contract! Sources confirm to me exclusively that Cuthbert has inked a deal to reprise her role as Jack's lightning rod of an offspring for a season-ending arc that will no doubt trigger a new round of wholly outdated and painfully unfunny cougar jokes. Per my 24 mole, Kim will return minus her old beau (sorry, C. Thomas Howell) and plus a child! That's right, Kim's got a little puma all her own!
