The weight of the mouse in the SI unit would be 0.02 kg.
Mass is the unit which describe the quantity of matter in an object, the SI unit of mass is kilogram.
And conversion factor of one pound to one kg is
1 lb=0.4535 kg
Now the mass of the mouse in Si unit is calculated as
m=0.4535*4.41*10^(-2)
=0.02 kg
Therefore the mass of the mouse in the SI unit is 0.02 kg.