She should contribute funds to the 457b because it's not an age based retirement plan, thus she will not experience any restrictions like an "early withdrawal penalty" if she retires before the age of 55/59.5. The only restriction she has for access is that she has to leave the employer by either separation or retirement. So even if she left or retired at 40, she can use that right away. If she has the option to make Roth contributions to the 457b, even better because chances are she's in a lower tax bracket now than she plans to be later.

It might be good to contribute to the 401k as well because the employer is willing to match and give her free money. That would work well to contribute to their at least as much as the match offers.

All in all, just put money away. It does wonders and if you have those supplemental options, use them.

I would not use the pcra through Schwab, because that's connected to one of her other investment and will probably cost her more than the gain, she should be able to make good investment choices just in the core portfolio.

As to how much to put in, well the 401k and the 457b each have a contribution limit of 18k per year, Roth or pre-tax so I would just do what the budget allows. Make sure to take care of any personal debt before over investing funds, no use losing money on those- settle them and then invest extra assets.