After completion of a certain amount of Hunters' Rumours, she will give the player various items that pertain to the guild's history. Players talking to her after completing 50, 100, and 150 rumours will be offered the tattered request note, guild history excerpt, and Apatura's key, respectively.
Lastly, players can talk to Guildmaster Apatura with their Hunter cape or max cape in their inventory to give them the ability to teleport to the guild, by the entrance to The Burrow.
This article on an NPC has an associated dialogue page. Click here for a transcript of possible conversations with this NPC. Click here for a list of other transcripts that this NPC speaks in.