Is it permissible for a woman to sit with her daughter's suitor unveiled before the marriage is consummated?

The wife's mother becomes forbidden to the husband simply upon the marriage contract with her daughter, based on the Almighty's saying: "and your wives' mothers." As for the engagement, it does not permit anything, and the fiancée's mother remains a stranger to the suitor, and she must observe hijab from him until the marriage contract is concluded.