The TurboTax interview is not clear enough in this section. Two parents living together cannot split the child tax benefits. The child can only be entered on one parent's tax return. The other must leave the child off their return entirely. The two parents can decide which parent is going to claim the child. It's not possible to guess which parent would get the most tax benefit. You can try it both ways to see which works best. Make sure whoever doesn't end up claiming the child deletes the child from their tax return before filing.
