Well, the MC has both Nightshade and Crowfoot genes, so it wouldn't be impossible to be attractive; a good facial structure is kinda guaranteed (I still don't know if I should add a comment or two here and there in the game). I guess I should have said alluring instead of pretty/handsome; after all, a good looking face without charm is kinda bland/not worth remembering.
The situation is not as simple as just Aquilegia not wanting to have kids
You're right on the heir part; there's a lot of pressure to have offspring (specially if your family branch is the one holding the title). In Datura's case, it's his sister who has the position of Marchioness, so """technically""" it doesn't matter if ("""if""") he has kids. Yet, everyone knows that shit happens something may happen in said line, and cousins may be needed.
Aquilegia knows this, but she also takes into account other facts; from their current situation to her future:
Datura's sister, Petunia, is happily married (or as joyful as these thing are since hers was an arranged marriage) and pregnant (the MC's cousin is only a few months older than them). It's very likely that Petunia and Stephanos (Bane) will have more than one kid, so the chances of Datura's spawn possibily inheriting are very low. She has no idea of what may happen in the future, of course.
So for starters, going through a pregnancy is already a big no, not worth it since it's not nowhere guaranteed that said child would hold the title someday. Also, the delivery could be complicated, needing a C-section (which it was needed in the end), making her undesirable for many. Remember, scars are a big deal in this world!
If she's unwanted, that limits a lot of her future marriage prospects (you can guess that she would need to get rid of her current husband), or heighten the chances of having an annulment. Because if said man later on discovered her scar, he could (publicly) denounce her for fraud (after all there's plenty of people getting "divorced" or declaring the thing null for petty reasons), which is worse.
So, long story short; yes, she was aware that someday she needed to have a child, but not necessarily Datura's.
Yep; Datura kind of lost everything, but he wanted to marry for love. He had to start almost from 0, and those were hard times. Mmmm... I don't know if I should add their backstory in-game or not.
If you ignore her, she will make sure that you'll notice/remember her, so better watch out; these types can't stand being overlooked. If a forced marriage isn't enough, she will find something else I would recommend you better take care of her in some way.
1,2m a 4 years old? I checked several records, and they are are about 90cm Plus, the MC is tiny, so they don't even reach said height.
Sorry, but this time it wasn't Aquilegia's fault @poison_mara is right, the furniture was made with certain kind of people in mind (those of "high status"), so it would be Datura's. Though he doesn't realize it, because back when he was small, servants helped him, and the MC is usually tucked either by him or someone of the staff, so he sees no problem, there.
@Underlurker there are several ways of dealing with her mortal or not, but you'll have to be careful. Everything has consequences, even more so if you're not careful enough.