Adding an additional motor to a load
Is this correct?


Yes.



For any future readers, the key formulae here are:

$$ P_{kW} = S_{kVA} * pf $$
$$ S_{kVA}^2 = P_{kW}^2 + Q_{kvar}^2 \quad\text{therefore}\quad Q_{kvar} = \sqrt{S_{kVA}^2 - P_{kW}^2}$$

Which can be derived from an example of the power triangle below and the fact that \$ pf = \cos\theta \$.