Can you please clarify exactly what your question is? I am assuming you are a US citizen or resident.
Are you asking if you sell at a gain is it taxable to you? The answer is yes. The fact that it is a foreign home is irrelevant. You can choose to file separately if you personally don't wish to have the tax burden, but your wife's standard deduction will be cut in half and she will pay a higher amount on the gain.
