GalacticCat's Things

I'm looking for this incomplete manga i read once and haven't been able to find again. It's about a young villainess, she was isekai'd i think? What I remember is that the villainess wanted to repair a love interest's family relationship and stop an event where a male love interest's mother dies.

They find out, secretly the mother had been receiving threating letters and that was affecting the family. When the li'l villainess heard the family was going on a trip (the event), she starts flailing on the ground like how a brat would to join them on the carriage and succeeds. (I believe the love interest was impressed and wanted to try but was embarrassed?)

Anyway, so both her family and his starts boarding the carriage? and li'l villainess closes the carriage door on the love interest's uncle. Bracing the door with her small hands she says something like? "LI's mother and father love each other very much and that uncle needs to get over his love for her and find someone else." The uncle then goes ballistic trying to open the door to kill them and the husbands of each family inside the carriage take charge and take uncle down! (๑•ㅂ•)و✧