Thanks for using JustAnswer.com! I will do my best to provide you with a clear and concise answer to your tax question based on the information that you have provided.
The fact that your fiancee has cash and property in China will not create a tax issue unless there is income (rent or capital gain) from the property, or interest she receives on the cash. She may need to file disclosure reports with the IRS about the cash (See FBAR, and Form 8938 )
If your fiancee is taxed as a US Resident Alien, she will need to report any income from the property that she holds in China. She will be taxed as a resident alien if you file a joint return with her after you are married. She will definitely be a resident alien after she has her green card (See this site on determining whether she is a resident alien or a nonresident alien)
Conversely, if she is a nonresident alien and you do not elect to treat her as a resident alien after you are married so that you can file a joint tax return. She will only report US source income on her US tax return. (See this site on nonresident alien taxes) Keeping non-resident status as long as possible may be beneficial if the income on the cash and property is substantial.
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Hi, sorry Phillip for the radio silence. Thank you for your quick response! During the time she starts applying for her green card but has not received it, what is her tax status? If she wires in cash into a bank account in the U.S. does she have to report and be taxed for doing so?