Hi and welcome to our site!Several issues...I assume that your girlfriend is an US citizen or US resident for tax purposes.The fact of transferring funds is not reported to the IRS and not is not taxable.However - the sale transaction should be reported regardless if funds are transferred or not.Her taxable gain will be calculated as (selling price) - (basis).The basis is mainly her purchase price (assuming the property was purchased) adjusted by improvement expenses.If the property was used as a her primary residence at least two-out-of-last-five years before the sale - the gain - up to $250,000 for single person might be excluded from taxable income.The fact that the money will be used to purchase another property is not relevant in determination of her tax liability.
She is a resident . Question remains is how can she transfer the funds from Moscow to the USA? Thanks.
There is no issue with transfer.The buyer or her aunt (acting as her agent) may simply transfer funds to her US bank account via wire transfer. She may want to contact her banker to obtain information about international transfers and bank requisites . There is no limitations on transferred amounts as long as she doesn't carry cash over the border.
You are welcome.