Actually, I've had a tama adult mate at 5... but that's the lowest. (I know of)
Tama Stats:
Egg: Pink with yellow buttons
Girl ^_^
Viole
2 years
Teen
Ichigotchi
Training: 8
Egg: Lavedar with dark purple buttons
Boy :D
Chip
1 year
Teen
Ichigotchi
Training: 4