A former client is concerned because their previous lawyer, who handled their inheritance case, is now representing their daughters in a partition case against them. This presents a clear conflict of interest, as the lawyer possesses confidential information about the client's strengths and weaknesses. Generally, lawyers are prohibited from acting for an opposing party in a related matter due to their duty of loyalty and confidentiality. The client can petition the court against the lawyer, and courts have the power to prevent a lawyer from appearing if it's deemed improper.