I’m working to upgrade her, and right now all of her skills are at maximum level, but I keep finding that her Silence skill keeps failing to work. The hits don’t miss, and the enemies have no stacks of Hardy, but it barely works?
So my question is if I should work to upgrade someone else, or will she get better with higher tiers?
…you’re thinking of blinds
Oh no, what I said also regards to Evades.
Tia Dalma is great… can you specify what enemies you are fighting?
She is good with silence teams. So, If you’ve silence characters up, then you should upgrade Tia.
Who would make up a Silence team? I’m just using her in a Study team as a means to Silence opponents.
I’m trying to use her in PVP.
Disgust, Angel(St), Tia(Ya) would make a good silence combo, maybe add Li Shang(Mu) for additional buffs and protection and silence via his Mu disk. Drakken will be a nice addition too! Or Meg! 
Hope it helps! 
Well This PvP season maximum of these silence characters are not really useful. So is Tia Dalma.
Therefore, I recommend to upgrade Mr. Big or Kristoff. And someone who knockbacks! And also a normal damage dealer.
Then it’s because of the rule. No damage so silence
Carl can go great for a silence team tank.
And Sadness 
Imo, Sadness is better. She can remove stacks of hardy pretty quickly with her white skill.
My Tia Dalma team is currently comprised of her, Disgust, Genie, Timon & Pumbaa, and Dash.
Everyone’s fast as Hook, booooiiiii.
It does, thanks.