This page of our guide to Psychonauts 2 lists the Nuggets of Wisdom available in Lucrecia's Lament.
There are 3 Nuggets of Wisdom in this level.
1st Nugget of Wisdom
Location: Flea Circus.
To reach this secret, you have to jump on a wooden platform. You can easily access it by jumping on the ropes.
2nd Nugget of Wisdom
Location: Nona's Quilts P1.
This Nugget of Wisdom can be found on a branch, right at the exit from this part of the area. You need to jump onto the needle cushion, then bounce a few times and jump onto the branch where the secret is.
3rd Nugget of Wisdom
Location: Nona's Quilts P3.
You can reach this secret by going through the tunnel. You need to open it with telekinesis.