Shield of Urskaya (14 Brown)
Give an Ally [Magic + 1] Armor, boosted by all Enemy Attack. Then Enrage and Barrier them. [2:1]
As you can see, it‘s going to be something capable of giving Rowanne a lot more than 70 armor (at least in scaling content), so it should be pretty fun 
I’d also consider at that point speeding the team up a bit — try replacing the Royal Engineer with something like a fully-traited First Mate Axelubber, Daughter of Ice, or Gimlet Stormbrew — any empowered converter, really, now that I think about it, because Scurvy Seadog, Drowned Sailor, and Moon Rabbit would all work well enough, too, depending on how tolerant you are of slight mana-blocking.