I appreciate all the replies so far.
@Spaarwalvis - I would say, yes, rebalancing is too much for this individual, but not necessarily for me. (ok, it's my mother... I was purposely vague in the op). As a bit of background, this is more money than she has ever had in her life. Her impression is that "Stock Market" = "Bernie Madoff", (one of her pensions got burned by a ponzi) and she saw a number of her friends in S&P500 funds panic when they "lost half" back in 08/09 (but didn't recognize the subsequent recovery and resurgence in the following decade). So I have had to educate her on why including some solid blue chip stocks in the portfolio is a good and necessary thing, why the friends only "lost" if they sold low and stuffed it in a mattress, etc. In time I hope that she can take gain more understanding and take some ownership of the portfolio, but perhaps right now when we are all mourning is not a good time.
The tax treatment of the various accounts is the one thing I do not have a good grasp on yet. I understand that bonds produce taxable income, rather than stocks that produce LTCG and qualified dividends potentially taxed at 0%, so put bonds in tax-advantaged and put stocks in taxable. However, in her case, for such a low income, does it matter at this point? Her income is going to look something like this:
16.5k social security
13k pensions
10k ? income from taxable funds (4% of 250k)
3k - withdrawals on the pre-tax accounts (~ 4% of 73k)
42.5k / yr total
Since social security is not taxed, that leaves ~ 26k of taxable income, some of which will be LTCG / Qualified and some as regular income. Some of the regular income would be offset by the standard deduction, and the LTCG / Qualified div's would be in the 0% bracket anyways.
I should also mention that I am inclined, for the time being, to put 250k of the taxable into VWIAX, at least for the first year, to get us over the hump of losing family members and having to clean up their estate etc, and not let perfect be the enemy of good. Am I missing anything huge here?