OF NOBLE BIRTH
This quest only begins if the Warden is a male dwarf from the Dwarf Noble Origin and had relations with Mardy during the origin story (either alone or with Teli).
Mardy
Teli
Walkthrough
You encounter Mardy in the Diamond Quarter when you return to Orzammar. Because of the caste system, the Warden's son takes the caste of the father and because of the Warden's exile, Mardy's son is now considered casteless. It's up to you to restore the child's birthright. Furthermore, the Warden may also elect to give Mardy some money in order to properly accommodate herself and their son until the election is settled. By choosing that option you can give her 1 Gold, 10 Gold , 50 Gold or 1000 Gold.
During Orzammar's main quest talk to either Prince Bhelen or Lord Harrowmont and ask them to accept the child into their House. You can only do this before either one of them is made King (or shortly afterwards), else the child will remain a casteless dwarf.
Result
Your illegitimate son regains his status in the royal house or your son remains casteless. If he regains his status, you are given the chance to name him. Amongst the names you can choose are 'Endrin', 'Trian', 'Duncan', 'Gorim' or after the Dwarf Noble Warden. If you let Mardy decide, she will name him Endrin. The name 'Trian' will not be an available option if you killed him during A Noble Expedition.
Notes
If the Dwarf Noble had accepted the noble hunters' proposition (only possible as a male), Gorim Saelac during A Noble Expedition, will have some remarks about it which would vary whether Mardy joined the Dwarf Noble or both Mardy and Teli.
Bhelen will refer to Mardy as casteless, even though she appears to lack the brand.