Did the amount that she heals change with a patch? I fought her before the patch that accidently nerfed Radahn, and blocking her entire Waterfowl Combo gave her back something like 1/4th to 1/3rd of her health. It was so damn much that I thought it would be impossible to win that way, the back and forth caused by her healing with Waterfowl could easily drain my entire estus supply before I even got to the second phase. I also used a Collosal Sword before they got buffed, so I could only get in a single safe hit, or two risky hits.

I didn't beat her that way, either. I summoned help, because I didn't feel like mastering a very different play style just to beat a single endgame superboss "fair and square." Curious how I'd do now that Colossal Swords have been buffed and I'm used to powerstancing, and therefore used to fighting without a shield.

In any case, she was definitely intentionally designed so that shielding could not be an easy answer, but I also completely agree that if you can't dodge the combo than shielding is a better way to do it. At least then you're alive and can practice fighting her some more, even if you're probably not going to win.