Is it permissible to perform Umrah on behalf of one's fiancée, sister, or mother, while residing in Kuwait, given the inability of family members to come from Syria due to circumstances or financial constraints?

An 'umrah performed on behalf of a living person who has not yet performed the obligatory 'umrah is not valid, unless that person is completely incapacitated and has authorized another to perform it on their behalf, and the one performing it has already performed 'umrah for themselves. If the individuals mentioned are able to perform 'umrah themselves, then an 'umrah performed on their behalf is not valid, as their current incapacitation is temporary and may be overcome.