Either it's the case of the prince is a dumb brick and misunderstood the situation (and the heroine couldn't say anything because of social positions or he didn't believe the 'victim'), or the heroine is secretly a bitch (kinda unlikely from these quick montage)
At this point I'm just curious about how she screw it up.
Really is it so hard to just not get in contact with the heroine? Just not care about what they do...
I hope the heroine isn't a snake and that the prince isn't a dumbass hoe. I hope that the heroine and prince have a respectful relationship with mc if they do fall in love and try to work it out with her calmly and kindly and are apologetic about it.
She is looking pretty determined to make it work, but from the summary we already know she is going to majestically fail, but what it is she could have done for things to go so wrong to the point of being thrown away ? ^^; Unless, like some other users said, the prince is just no good and anything she does is useless either way...