The House of Hope isn't only named that because Raphael has a weird sense of humor. It's also literally the House of somebody named Hope that Raphael is keeping hostage in the House of Hope, right at the center. In order to free her you need to grab the Orphic Hammer from the House of Hope itself before making your way to her location. But should you even consider freeing her in Baldur's Gate 3?
Should You Free Hope?
There's no real downside to freeing Hope. She'll basically beg you to help her so if you don't you'll feel REALLY bad (unless you're a sociopath), and she's got some incredible abilities that you can use in your battle against Raphael. Make sure you make your way to where she's held captive, defeat the fairly terrifying jailors that include two different Spectators, and bring her with you to the Raphael battle.
Hope has the ability to 'Revoke Guest Status' of anybody in the house that isn't Raphael himself that she can cast twice, which means you can get rid of any two difficult-to-handle enemies without having to fight them yourself. Sadly you can't keep Hope in your party after the fight, but she's such a huge boost to your team during the Raphael fight that you should free her even if she dies in the battle itself.
Hope won't appear again in the game, unlike several characters who will take part in the final massive battle against the Absolute, but her help is something that can't be sniffed at in the context of the fight that she's actually available in.