It was just another story of a long marriage ending in divorce. But for Amy Reiss, a matrimonial attorney, the difference was that this broken marriage was her friend’s. As tears welled up in Ms. Reiss’ eyes upon hearing the most intimate details of her friend’s life, she realized that she could not represent her.

Lawyers are often besieged by friends and relatives seeking legal help. These can be complicated situations, where it is as difficult to decline a request for help as it is to accept. Although some solo and small-firm practitioners see representing family and friends as an opportunity for business, others avoid the situation entirely. Every attorney interviewed warned that rules have to be set when a friend or relative is a potential client.