Aren't pets supposed to evolve faster than Heroes ?

I have to do a mission in NF that includes Meloni, who was only lvl 10, so I got her a lvl 12 Aggressive Lion pet, and started to level them both up. When Meloni reached lvl 20, the lion was still only lvl 15, and I had read in GWiki that pets evolve a lot faster than players (or Heroes)...this doesn't seem to be the case, since the pet was with Meloni the whole time. Anyone else notice this ?

Pets usually do level up quite quickly, but there's one piece of game information that applies here:

If a hero is behind your character in terms of level, the hero will get boosted experience from combat. I'm guessing that your character was level 20 at the time, so with Melonni starting out 10 levels lower she would have been getting an absolutely stupendous amount of experience while the pet would have been getting the normal amount of experience.

Heros below your level gain exp 5 times faster then a human player. Thus why heros level up faster then pets.

...thanks for your replies...I am wiser now !

Heros also get XP from quest rewards, pets don't.