State tax filing

I believe you still have to allocate the income manually on the New York return because Turbotax isn't capable of allocating it on its own.  Sometimes income is taxable in two states (if her permanent home was in one state and she was working temporarily in another state) and Turbotax also can't assume that income should be allocated by any particular method.  How would Turbotax know how many dollars to allocate to New York?