Is a relationship that began with an online acquaintance, then developed into a promise of marriage after three years and a request for personal photos, considered a wrong start to a marital relationship, and how can one inform the family about such a future commitment, especially if the young man is from a different country?

Communication between a young man and a young woman who are not mahram (definition) (marriageable kin) is forbidden and a means to fitna (temptation/strife), and one must repent from it. The wrong start to a relationship does not necessarily mean failure in married life, but one must follow the correct principles for choosing a spouse, such as asking trustworthy individuals about the young man, especially with the difference in countries and customs. Verse 235 of Surat Al-Baqarah pertains to proposing to a woman in her 'iddah (definition) (waiting period) and is not general for all women. Sending a picture to a suitor (khatib) is permissible, but in this case, he is not considered a suitor, so it is not permissible for him to see your picture.