Aww man, that last part made me sad. Idk how optimistic or nihilistic you are, but either way, I hope you get a shot at attaining the kind of life you want, even if you think it's unattainable or too good to be true. You are a sweet person.
And as for Orphelith, you're right that we don't know much about her. But I don't think she's that different from the others I listed, hear me out:
1. Orphelith is probably a romantic, but very good at not showing her soft/vulnerable side. As we know, she had a tiny king that she loved and respected, and ruled alongside. And since his death 10 years ago, she's still in mourning (or has not take a liking to anyone else?). Either way, we know that her ideals were very different to his, even putting them at odds sometimes that he'd be stealing from the palace behind her back. She even indicates that she felt he was too naive and optimistic. But despite all that, after so many years, she still dresses in black and tries to keep his memory alive by maintaining the laws that he advocated for, even though she personally dislikes those laws. Her regime was more strict than compassionate before that man, but because of him, it turned more charitable. There's something so beautiful about it, the way she acknowledges him and remembers him fondly. Almost like there's always a part of her thinking "what would he have done?". All that makes me think that she's one of those people who loves the hardest but shows it the least.
2. She treats the MC well. Even when she catches us in the wrong place(like when we wander into her room) or when she's suspicious of us being a spy. She doesn't belittle us or order us around. As long as you're courteous, she treats you the same, even cracks jokes with a straight face(fricking love that!). She demands respect, but not while treating you as inferior. I remember there was 1 time where she says something like "know your place, human!" but she says that if I choose the pervert option while sneering at her boobs (completely deserved in my opinion. I didn't like choosing the option, but was curious. I re-winded and went with what i liked better). As long as you respect her, she respects you, treats you like an equal, even hears your opinions and stances without judgement. And as I'm expecting in the future being her personal assistant, she'll probably ask our opinions in a lot of decisions (while still making the final call)... like the role of Corvo in the Dishonored games (except rather than being the Royal Protector, you'll be the one being protected cos ur tiny

). Maybe later down the line she has enough faith in you judgement that she'll let you influence her decisions and even rule in her absence(tiny king path unlocked?)
3. You can't suck up to her, the only path to her is through respect. She won't entertain a pervert or wannabe slave, but a respectable gentleman(very queen-like

)I think near the beginning of the Tiflame(i made up the spelling) route, we even get the option in our first meeting with the queen to be her servant, choosing which does literally nothing. (u can choose the "I'm in love with you" option, or the other one, but the queen doesn't give a shit.) I fricking loved that decision so much. Because it shows that Orphelith doesn't want anyone sucking up to her(even if it's for sex) and the only way to her is through respect and caution. She'll entertain you if she sees you as an equal, but not as a slave. And I know in that place the path is a deadend because the developers probably didn't think of adding her route until later, but the story is so much better because of it! And I love it because it makes her slightly different to other intimidating giantesses in the Hell route: Nyxmay, Kendra, Yaku, Pyeka... they all love it when you suck up to them, but not Orphelith. And I love that! (Obviously this isn't to put down anyone who enjoys the hell path!)
4. A lot of questions arise when wondering if the queen would be a good romantic fit...
How can she love the MC when she still thinks so often and so fondly of a past love?
If she does do things with the MC, would she feel guilty constantly and not give him the same affection she gave to her previous lover?
Would you even consider her a romantic if she falls in love with MC? Does that mean she didn't care about her previous husband after all?
I think these questions arise from the idea a lot of people have about romance that there can only be 1 true love... I mean sure, maybe. But when one of them dies or needs to leave and the other spends the rest of their life pining over the other even when they clearly want to love again or are horny, but decide to abstain out of some misplaced sense of duty... it's not love, it's some freaky mental illness! If being single makes you happy or if you're just grieving, that's fine. But if you really want to love again, but you deny yourself that, you're not doing it out of love for your past lover, but out of shame or guilt. So I think even with a past relationship lingering on her mind, she could turn out very sweet and romantic. Of course, we run the risk of her never loving us as much as she loved him, but that's a risk the MC should be willing to take. I don't think for it to be super romantic, there has to be only 1 person in your mind ALL the time. She'll probably bring him up every now and then, and I'd be fine with that. But if she brings him up in a way that ruins the moment, she gon get an earful from me (yeah, that's right! Me, the tiny, will scold the most powerful giantess in all of existence if she overdoes it! Pray for me

). Hopefully that won't happen.
5. Also, would you like to elaborate why Orphelith stands out so much from the rest? Is it just because she seems more intimidating than the others on the list?
EDIT: It was 200 years ago when Orphelith married, idk why I remember 10 years ago? Just replace 10 with 150 or whatever.