Speaking as someone newly minted in your DW's situation....
DH died earlier this year, and we have no kids. We went to an estate attorney in 2015 and set up wills and trusts, and also redid a slew of individually held brokerage accounts at different companies, moving all of them to Vanguard and holding them JTWOS (though he was the primary owner on one of them, and I was the primary on two others).
The house is jointly owned (entirety), and by law we were each other's 401k beneficiaries, as well as pension beneficiaries. It was decided that his old rollover IRA and company life insurance would go to his siblings via beneficiary/TOD designations.
It was also then written into our wills and trusts that everything else would go to the surviving spouse, and that the surviving spouse would then leave everything to all the siblings and nieces and nephews.
We of course did not do all of this planning with the expectation that it would kick in less than two years later. But it worked out really well in that his siblings are splitting low-six-figures now, instead of having to wait until I kick off before they see anything. The nieces and nephews are still young, and so it's not a bad thing that nothing went to them in this round.
I now though have to redo all of the beneficiaries, deciding which pots of money should go directly to my trust and which ones should be TOD. House will be retitled to be owned by my trust, as will the taxable brokerage account. But the inherited IRA from DH's 401k and my own rollover IRA should be left to individuals, not my trust, so I am figuring that out. Thank heavens Vanguard lets you do that online.
Now, I could live another 40 years and have five more husbands, and we didn't write the trusts so that I am required to leave anything to his family, since I can rewrite mine at any point. But I seriously doubt I will ever marry again, and it might be good to have his nieces and nephews to maybe want to be nice to me when I'm old, if they think there's something coming.
I don't know how involved OP's DW is in the finances of the house, but I was pretty much the driver of the estate stuff and the brokerage stuff, so I have a much deeper knowledge of all of this than she might have or want. And to be honest, it's given me something to do in the midst of such a terrible time.
And one other vote for the estate attorney--ours is priceless to me *now* for the handholding about what needs to be done, when. Don't discount that when thinking about whether to go to one. It's not just about whether you think you need help with the planning, it's about whether you think DW will need help with the execution.