@nikki20201 , did your mother actually transfer title ( Escritura ) to you or is it just an understanding/ declaration. If the title has been transferred -- then your basis in the property is her basis ( in this case acquisition basis + any improvements she may have made during the intervening years. If there is no "escritura" then you have to recognize the rental income but the basis will be FMV at her passing.
Start of service ( if the property is in your name ) will be the day you took possession of the property
Do you need more help on this ? If so please answer if you have the escritura in place and in your name--yes ?
