She needs to gain full immortality in smaller steps, then.

After drinking the Elixir, she would have a part of that immortality (for example being unable to die, but she'd only heal back to a state where the injury isn't critical anymore, all healing after happens at a normal rate) Between two and three separate echoes would be required to get the full deal.

So a possible Tier 2 echo would be: The Elixir with diminished powers.