I swear, I know the Prince meant well when he gave her a title and all but the poor girl s...

I think it was deliberate to reward but also keep her close.

I agree, pretty sure he caught on that Marie wanted to run.

Keep in mind this is a different era and when she said “I want to be free” the prince implied it as free from being a war slave. Someone who made a huge ass contribution to the country can’t just go out of the castle as a commoner. The ML has his duty as the crown prince to rightfully award his people, which is why he bestowed her a title which he says “an award greater” otherwise his people will question his ruling

She wanted to swim but she got hot springs for herself.

I agree to that too.