YA novel set in the fifties, possibly about time travel

[Mackenzie]

I read a book when I was in middle school and while the plot is slightly fuzzy since it's been so long, I believe the protagonist worked as a receptionist during the fifties (forties?), and for some reason I recall there being time travel involved but I'm not 100% sure about it (it might be because I seem to remember the word 'time' being in the title). The only scene that I really remember all that well is her being harassed by someone she worked with, as per the time period. The jacket's what I remember the best, it was pink and I believe there was a silhouette of a girl as the art. I would have read it probably in 2011, so it had to be written around then or a few years before.

I had just sort of picked it up off the shelf in my school's library and ended up being distracted by other novels so I never finished it, but it stuck out in my mind as good despite not finishing it and it's killing me that I can't find it no matter how long I search the internet. I'm not entirely sure if anyone will know what it is, especially based on how little I remember, but I thought I would try anyway.

[Andy]

This makes me think of Van Vogt's "Masters of Time" but that is really old Masters of Time

[Kate]

This sounds like at could be one of Heinlein's "juvenile" novel, but I'm quite familiar with them and it doesn't fit. The closest ones would be Time for the Stars or Podkayne of Mars. Neither of those is a fit, but your description fits the tone of your description.
Time for the Stars
Podkayne of Mars