None at all. I think changing her name would have possibly caused a lot of problems with wife's pension, investments, banks, insurance, etc. in Taiwan. Keeping her name has not caused any issues in the US (Taxes, Military ID, Military Health Care, Social Security benefits, Medicare, etc). As far as passports, it has never been a problem since everything has been in her Taiwan name. As a dual citizen, both her Taiwanese and US passports are in her original name.