Ada Laird is a NPC in Divinity: Original Sin 2.
Hi, here is what we did to box her in for a semi quiet Merchant square. https://imgur.com/IooMDIa
This NPC nearly drove me insane with her cycle of small-talk. That is, until I figured out that at the point X:337 Y:117, the point directly west of the statue where the grass intersects with the cobblestone... Ada makes a brief pause which allows you to trap her by surrounding her with barrels. From this point, everyone is too far away from her, so she stands there quietly.
Quite possibly the most frustrating NPC in the game. It is recommended to relay teleport her to outside of the square and kill her.