Who wins the fight?
A great frustration when preparing income tax returns happens when your “kids” decide to file their own returns and that interferes with the parent’s income tax returns. Each situation is different, you could employ a child to work in your business and pay less taxes, you could lose exemptions or better yet college tax credits.
You could also lose EIC credit or an additional child tax credit or daycare deductions. I found a daughter “secretly married” while living at home and attending college, then filed a joint return with her secret husband that created tax problems for both the parent and child.
I normally find it is more advantageous to prepare the entire family’s tax returns and tax the deductions where best utilized.