We are married filing jointly. I overpaid taxes and get a refund, and she underpaid (owing), but we only see the combined result. Is there a way to see a breakdown?

[Zbucklyo]

Not explicitly because your income and tax liability are determined by combining all income and deductions together.

You can prepare two mock married filing separately returns to get a better handle on what is happening, but everything will not necessarily add when comparing this to a joint return.