you need to have the money in the account for 2 months (2 statrement cycles)
. Otherwise, the mortgage bank is going to ask you where the money is from
and you would have to provide the proof for the gift. You also need to
provide a letter from the chinese bank of which you father-in-law had
transffered the money from. The mortgage bank will also charge you a few
hundred dollars for translation.
Save yourself all these trouble by having the money in the account for 2
months.