In such a story, financial challenges can also be part of it. If the teacher loses their job because of the relationship, it will affect their income. And for the couple, they need to adjust to a new life together while dealing with all these external pressures. There may also be a challenge in terms of equality in the relationship as the previous teacher - student dynamic might still have some subconscious influence.
Well, in the 'I married my teacher story', a big challenge is probably the professional consequences. For the teacher, there could be issues with their job, like facing disciplinary actions or losing their position. Also, socially, they may face isolation as some people might not accept this kind of relationship.