My parents will transfer some CNY to her China bank account, and she will give me some cash in USD or transfer with US banks.
If the money will be wired to you from someplace outside the United States, and the amount exceeds $10,000 it will be reported to the US Government. If your friend gives you the cash then when you buy the car or deposit the cash, it will be reported to the US government.
Does it count as gift so she has to fill 709 form?
MaybeIt might be a gift. Do you have to pay it back? Are your parents US citizens? Is your friend? Once the initial form is submitted to the US government you might have to explain the transaction so the IRS doesn't think you were hiding income, or you had a undeclared foreign bank account.