Without making Brigitte OP but want her to maintain her core identity, play-style, and mechanics.
As an actual Brigitte main, I prefer to be a sturdy healer with low healing. The play style that many Brigitte were drawn to was a frontline, brawling healer. And I don’t need to be a main healer to do that. A good off-healer can still provide plenty of utility for the team, if they are good. The key is to make her fun again. Right now, she's just a Whip Shot/RP bot.

If Zen is just a DPS hero that has some healing, I want to be a tanky healer with some healing and low damage (but more utility).

Maybe, to balance her, they can limit the range of RP but add just 20 armor to it (just so the ability feels like it has some oomph to it). But limit the range to 20-30 meters so that you can’t yeet it and instantly save a life from across the map. And 20 temporary armor (unlike the previous versions of 75, then 50 armor) isn’t enough to make even flankers OP either.

Give back her HP and make sure the shield isn’t tissue paper anymore but reduce damage of Whip Shot to maybe 60.

That way her weakness are clear. She needs to be with her team to be effective and she can be zoned out pretty easily (essentially, like a mini-Reinhardt but with a lot less HP and barrier HP). Reducing her damage, combined with her lower healing, means she wouldn’t be a must-pick and she can’t combo kill a full health flanker, but be able to shoo off a DPS coming after her support buddy.

And she wouldn’t be just flat out better than Lucio. Because Lucio would not only have speed boost (still one of the best utilities in the game) but he would have higher healing and much more mobility. Brigitte lacks escape mechanics others have, lacks any range, and would lack damage too.

In the end, I just want my favorite hero to be fun to play again. I want to brawl (and survive) and heal my team without everyone hating my favorite hero and constantly calling her OP.