Family Battler of Eastern Kingdoms

For all the trainers' waypoints:
/way Elwynn Forest 41.6 83.6 Julia Stevens
/way Westfall 60.8 18.6 Old MacDonald
/way Redridge Mountains 33.2 52.6 Lindsay
/way Duskwood 19.8 44.8 Eric Davidson
/way Northern Stranglethorn 46.0 40.4 Steven Lisbane
/way The Cape of Stranglethorn 51.4 73.2 Bill Buckler
/way The Hinterlands 62.8 54.6 David Kosse
/way Eastern Plaguelands 67.0 52.4 Deiza Plaguehorn
/way #32 35.4 27.4 Kortas Darkhammer
/way Burning Steppes 25.6 47.6 Durin Darkhammer
/way Swamp of Sorrows 76.6 41.4 Everessa
/way Deadwind Pass 40.2 76.4 Lydia Accoste

At this time you can only battle the trainers once per day. EK has to be done on an Alliance character and Kalimdor on a horde character. Being in a raid group doesn't work and you cannot abandon the quest after "completion" - therefore this Family Battler achievement will take you a minimum of 10 days/resets to do.

Beast

For all EK, Kalimdor and Northrend Family Battlers - Beast I used the same team

Infernal Pyreclaw P/B (Adrenaline Rush, Cleave, Great Sting)
Zandalari Anklerender P/S (Bite, Primal Cry, Black Claw)
Tarachnid Stalker (or any Spider) S/S (strike, Brittle Webbing, Spiderling Swarm)

I kept Great Sting up as much as possible, spammed Cleave. If Pyreclaw died I brought in Ankle render and prioritized Primal Cry. I used Tarachnid Stalker / Spider to absorb high damage 2 round ability hits such as Fly, Burrow and Dragon Breaths as well as using Brittle Webbing + Spiderling Swarm together.