What should a girl do if she is proposed to, but the suitor insists on meeting her or speaking with her on the phone before proposing to her family?

Whoever intends to marry is permitted to look at the face and hands of the fiancée in the presence of one of her mahrams, because these are not awrah (parts of the body that must be covered) and by them, beauty and physical well-being can be discerned. This is recommended according to the majority of scholars.

The suitor is a stranger to his fiancée, so it is not permissible for him to speak with her in private or to be alone with her, because Satan would be the third. The fiancée should refrain from meeting the suitor or contacting him except in the presence of one of her mahrams.