Which of the following is an example of "representative capacity"?

In the context of notary practice, "representative capacity" refers to an individual acting on behalf of another person. The scenario where a mother signs documents on behalf of her child exemplifies this concept clearly. In this case, the mother is legally authorized to execute documents for her child, typically due to the parent-child relationship that grants parents the responsibility to manage certain affairs for their minor children.

In contrast, the other options do not illustrate representative capacity effectively. Individuals attending a meeting simply represent themselves; an attorney writing a letter is acting in their professional capacity but not as a representative for someone else; and a bystander observing a signature has no legal authority or role in the transaction. Understanding representative capacity is crucial for notaries as it helps ensure that the person signing a document has the proper authority to do so on behalf of another individual or entity.