I started zafaria at level sixty, and got out at level seventy one, you will probably get out at level 72,73, or 74, don't worry if you are to late to Avalon, even if you get there at level 76, you would be fine. so don't worry about being late.
I started Zafaria around Level Sixty and didn't finish until Level Seventy-Two. If you start or finish a bit earlier or later, that's absolutely fine! It all depends on how many side quests you have done from other worlds. I haven't done very many.