Help, I Transmigrated into an Interstellar Big Shot

After transmigrating to the interstellar age, her scumbag ex shows up with his mistress.

She thinks she's a good-for-nothing, only to discover the original owner's secret identities one by one.

And she even ends up forced into a marriage?

Scene One: “Actually, actually, I'm not your younger sister.” She finishes, then looks earnestly at her older sister.

Her sister flicks her on the forehead.

Her third older brother flicks her on the forehead.

Her father flicks her on the forehead.

Her mother flicks her on the forehead.

Her oldest brother tells her to show some proof.

Scene Two: “Let go.”

She clings to a man's leg. “No, no, I won't! Don't you dare look down on me. Hmph, I'll scream that you're harassing me!”

“...Go see a doctor and get your head straight.”

“I'm telling you, I'm perfectly clear-headed. You're not leaving until you go register our marriage with me today.”

System: [Host, wake up! We still have the whole world to explore, and the stars and seas to conquer. Men will slow you down when you're drawing your blade. Wake up! We can keep a few fish, but don't let one drag you away!]