I'm sorry, but in my opinion a Roth should only be tapped in a dire emergency. Once the money is out of the Roth, it can't go back. You lose all that tax free growth. For a younger person that's a huge loss over time.
If you are healthy and employable, I think the three months of expenses is a reasonable start. Fund the Roth's for you and your spouse and then think about how much more you need in savings to sleep well at night. That's what I would do in your shoes.
If you want to invest in index funds, Fidelity and Vanguard are both good choices for the Roth IRA's. Fidelity has bricks and mortar offices if you like to visit your money and the folks watching over it. They also have a cash management account which might be helpful as you grow your asset base.
BTW, life insurance can take some time to pay out. Those three months of expenses could come in handy in the worst case scenario....