I think she had a valid reason, and I struggle to consider myself doing something differently when the other option is to leave a kid, who is struggling to help his family, high and dry. I abhor lying but you bet I would for this, if the only other option was to not help someone I believed was using my help to do good (by saving money to buy a car for his family).

However, you’re not incorrect that the lie itself is enough to build mountains of fear about unfaithfulness in OP’s husband’s mind. I would do the same as OP, probably, but I would also understand why it undercut her husband’s trust in the relationship. It’s a bad place to be, I truly hope they can work it out because I understand both sides, honestly, but I very fully support OP’s desire to be a kind human.