"but shes scared that her theory is wrong!" Well wth she gonna do? Her current "crown prince" ain't lovable either so what now?
no, she already knows for sure that it's the real ulysses. there's no "what ifs" in her mind. it's just that liesel can't reveal herself to him just yet because it might tip off the real gideon that she has memories of her past. gideon knows that ulysses can't also confess his real identity because of 1) he doesn't know liesel has her memories, 2) for fear that she will be forced to remember traumatic memories (especially since he did kill her, albeit for her sake) — and because of those reasons, gideon effectively has him in his grasp, all the while monitoring both of them.
ofc there's probably a better way for it, but that's how it was presented anyway
Be adults and talk about it geez.
Like, just ask for confirmation and if it's not true then joke it off. Why torture yourself with "what if he's not actually that person?"
Also- talk to each other about your plans~ y'all doing it like the other isn't involved with the problem. Talk about what you learned and what y'all should do to fix the current problems geez