I'm gonna be contrary to the usual opinions, which generally reek of cliche favoritism and the usual business. I want Harper back, and as Bluebird. Most who say she "didn't work" say so under the veneer of envy that it wasn't "their" Bat-person in-costume and heroing. Further, Harper can still be the "civilian perspective" and not abandon her costumed identity for when she needs to make use of it.

I do agree that Harper being a helper for those who need it is a good idea; Harper's appearances generally can be summarized as such in one way or another, not to mention stepping up to take care of herself and her brother. She should have agency of her own beyond that, however, and that agency should be given focus.

One thing I will say is that I'd definitely want Cullen to be prominent in whatever way that Harper returns. Best case scenario in a dueteragonist fashion, or close to it. One of the things I love about Harper is her relationship with her younger brother. It's one of her most endearing traits, along with her tenacity. And I loved Batman and Robin: Eternal for giving Cullen some spotlight. If anyone could work "behind the scenes", it's Cullen, based on his time near Eternal's end working with/under Midnighter. (I'd also love for them to still be in contact, for character-relevant reasons, but that's another thing.)