Even upon completion, this seems to be nothing more than a sentimental quest based on the player's mother.
Throughout your coursing through the party at Chateau Haine, you will probably find things called Caprices. Caprices are just coins that, in this quest, you throw into the fountain. There are five in total. The locations are as follows:
There are two sitting on benches around the party: one behind Leliana, and one on a vacant bench.
There is one in a sack near Leopold the wyvern.
There is one in the 'Other' section of the quartermaster's shop near the banquet area.
Lastly, there is one you will receive from Lord Cyril when you progress along in the quest, Heart of Many. He will refer to what your player refers to every time you get one and toss it in the fountain, which is how your mother would have appreciated it. He tells you it's an old custom and he gives you your fifth.
This quest is worth one attribute point, but you can't use it until you get inside the castle.