This would go in Socialize, not Tail Wags. Moving. ^^

Answer: Head to the Trading Post. You can type "3" for the owner spot, then your wolf names in their respective parental slot (sire/dam) and hit enter. If there is a relative still in the game, then you'll see their children in the results. You repeat this until you get no more results (or back track and try other relatives), then check the last result to see if they have any living offspring.

I hope I worded this right, and hope this helps.

Edit: It does not seem that there are any existing descendants aside from their daughter, Angelic Souls.