Is it allowed for a girl to take off her hijab (and show her hair) in front of a person who visits her home for a marriage proposal?
It is permissible provided that four conditions are met:
1. Both parties are immune from falling into sin, such as gazing with lust.
2. The proposing person has not previously seen the girl without her hijab.
3. The proposing person is more than likely to proceed with the marriage.
4. Based on obligatory precaution, the purpose behind the proposing person looking at the girl’s hair and other physical features is not for comparing her to other girls in order to make a decision, rather his mind should already be made up to marry her.