However, if you happen to work with someone who is getting divorced, don't panic! This is not normally how things work in Scotland. Firstly, it is unusual for anyone to have to give evidence in court in a family action. If the divorce is undefended - that is, both spouses agree to be divorced and there are no other disputes - witness evidence is provided via sworn written statements, known as affidavits, and nobody has to come to court.
Secondly, even if the action is contested, most cases are negotiated to a settlement close to the hearing (or even on the day!) and do not culminate in a full-scale evidential hearing with witnesses taking the oath and giving oral evidence.
It does happen, however, and we know witnesses as well as clients find this stressful, so we try to do everything we can to make it easier. For example, I was surprised that the lawyer dealing with the American case had not contacted the letter-writer in advance. I think anyone would prefer to have a courtesy call at the very least, rather than the first contact being a formal witness citation (the Scottish equivalent of a subpoena).