I've worked many places that had a wait period of 6 months-year. It's pretty common.
In the meantime, yes, she's out of luck until she hits 1 year for maxing that account. But she could make sure she can kick over every cent of her paychecks as soon as she's eligible to be in the 401k to try to load as much as she can into her 2016 contributions (meaning she might not have any pay coming to her towards the end of next year if the company does allow this, so plan accordingly. She can then set her 2017 and forward contributions to be spread out over the whole year.).
If you both aren't over the income limits, you can still both open traditional IRAs and max out those this year and going forward. It is 5,500 each, so if both of you do it, you'd have 11k into tax deferred and if you can do the traditional route, you can get credit on your taxes for the traditional IRA contributions. And come January 1, you can throw in another 5,500 each and get 22K into tax deferred within a few months' time. The tax credit does not apply if you are doing Roth IRAs, so be aware of the advantages/disadvantages for your situation before jumping on one or the other.