I am an estate planning attorney in Des Moines.
Some attorneys do inheritance tax returns, and some do not. I personally have done a few of these in the past month.
Many parts of the return are similar to the estate inventory for probate proceedings, so often the lawyer handling the probate proceeding (if it was intestate or will) will have the information you need.
In general, if you are not a direct child of the testator, you will owe money on the inheritance for any assets which aren’t otherwise taxed as income. **edit for clarity** Most assets are NOT considered income when inherited. Things like bank accounts, cars, real estate, etc.
However, if you’re inheriting some types of IRAs/401(k)s/403(b)s as a beneficiary, there won’t be inheritance tax, but instead it would be taxed as income for you as you take the money out over time. Depending on whether there were a few specific types of trusts put into place by the testator, this can be quite complicated from a tax perspective, and the laws changed significantly in 2019.
Most well drafted wills/trusts will explain whether the tax is to be paid by the beneficiary or the estate.
If you know the attorney handling the estate, that’s probably your best bet for who to reach out to.
As a nephew, if she died last year, it will end up as a 6% inheritance tax on the assets passed to you (other than qualified retirement plans like IRAs or 401(k)s).
I would also second the comment that suggested a revocable trust. Typically they are more expensive than wills (due to drafting costs and the amount of work with retitling assets), but if done correctly, you can avoid the probate process altogether, which can cost up to 2% of the entire value of the estate.