Probably.
Interestingly I'd put money on if you were to actually ask TCB, give her all the context and history and she'd probably agree that a Boston marathon time is unlikely even with all the hardest work in the world. Would be an interesting experiment though. Much as I love TCB, her unwavering enthusiasm does some times cross into unrealistic optimism XD
That aside, I'm also not sure how anyone who isn't a high level elite runner 'halves' their first marathon time - my first marathon a few weeks ago was a tit show and I finished in just under 5:30 hours, to half that I'd be coming home in 2 hours 45... well above 95% of the population who also run marathons.