If you received no Forms 1099-R, it seems that your share of the inherited IRA was moved to inherited IRA CDs by nonreportable trustee-to-trustee transfer which is the only way that an IRA inherited by a non-spouse beneficiary can be moved. Moving the funds to inherited IRAs means that the income continues to be deferred but you will usually have annual required minimum distributions and will have to completely distribute these inherited IRAs by the end of the 10th year following the year of your mother's death (although there as some circumstances where the distribution requirements may be different).
