A married woman has the right to open a bank account under her maiden name . That said, the assets deposited in this account will be part of the common property, which will be shared in the event of divorce.
As part of the fight against money laundering, I advise you not to deposit the proceeds of your friend's sale into this account.
1) In the absence of proof, your banker would declare this transaction to TRACFIN
2) In the event of divorce, the sum could be apprehended by the family court judge.