Which is your character's favorite: beef, pork, poultry, ham, venison, lamb?
I'll say poultry because she's giving me the vibe that she doesn't like overly fatty meats.

Does your character tend to overthink things (i.e. wonder why their patronus is their patronus) or do they just accept everything without questioning it?
I'd say she's not an overthinker in the sense of "omg does X person like me?"

Was your character educated in muggle history and sciences as a youth, or did their parents have them learn only things that would be relevant to them in the magical world?
Since the Lestranges are purist, I'd assume that she was taught magical things. Any muggle history would be terribly propagandized anti muggle.

Do your characters keep up with the regular happenings of the muggle world, or do they turn a blind eye to it?
She don't care about them muggles.

What is your character's "ideal" partner, if they so desire one? What traits do they specifically dislike (barring "stat-like" traits like blood status)?
Someone intelligent, ambitious and ruthless. She dislikes anyone meek without ambition.

How would your character react if a family member married a muggle or a squib?
Disown them.

Is their anything particularly notable/odd about your character's bedroom? Do they decorate it strangely, or does it look like what you'd imagine being the "norm" for their class?
I would say is a very basic upper class girl bedroom. I just now decided that she has a mini walk in library.

What is your character's preferred method of transportation?
Portkey for now, apparition when she gets her license.

What's your character's greatest insecurity?
I can't think of one omg. I'm sure she has one, it's just not the "her nose" kind.