motley fool at http://wiki.fool.com/Can_an_IRA_Inheritance_Trust_Have_Two_Beneficiaries_With_Different_Guidelines%3F#sthash.tzi432up.dpuf

Stated that a Trustee of a IRA Beneficiary Trust must be unrelated. I had not seen that restriction elsewhere.

Choosing a Trustee
The rules of an IRA Inherited Trust require that the trustee chosen is not related to the beneficiaries by blood or marriage. It can be a lawyer, CPA or a trusted friend. As these trusts will be open for many years, ensure that the person you choose is willing and able to administer the plans in the long run. The terms you set in the trust before you die will dictate what the trustee can do with the funds, but leaving the trustee detailed instructions of your wishes with regards to distributions to the beneficiaries will facilitate the process.
– See more at: http://wiki.fool.com/Can_an_IRA_Inheritance_Trust_Have_Two_Beneficiaries_With_Different_Guidelines%3F#sthash.tzi432up.dpuf