Here at TechRaptor, my colleagues and I have previously checked out the Starter Decks for Ursula's Return (linked above), as well as the Rise of the Floodborn set and the Into the Inklands set
As TCGPlayer points out, you can grow her attack power with something like Titanic Growth and then use Fabled Passage to double it again
The regular Ursula double-crosses her doppelgnger and seizes the trident to rule Lorcana alone
It's a somewhat demanding deck that will require you to plan your Challengers well and save valuable resources for the right moment, but it's also a fun deck that can be made much stronger very easily by swapping in a few more Evasive cards, like Genie, On the Job and Goofy, Daredevil
If we go way too safe, we risk the other thing, where the trading card gamers say, This isnt for me. I think the reason it took so long to get where we got was that specific target we were trying to hit to do something that we feel is welcoming, and strategically exciting for trading card gamers