
It's smart to me. Among all the powerful families in that kingdom, who would hands down do anything to help her? It's her father. Because he is a pos who's hungry for power. He can dispose of all the external danger and when the time comes, the Emperor and mc can dispose/cut off the Duke's power.
The manhwa did not do a good job in portraying the politics behind their decisions. ╮( ̄▽ ̄)╭

Well it's still a wrong move since she's not thinking ahead, the only reason she can stand strong as an empress is more or less because of her father who get rid of anything that could harm her position. He solved the problem with princess from another kingdom who even the ML struggles with, and even bring a profitable result for the empire.
The only reason Florin send those document to her is just to break her appart from her father's palm thus shaken her foundations that backing her as an empress. Making her a much easier target than before (since the ML is useless).
Gotta agree with Florin here, the fl is too Naive to the point that you would think she's actually dumb. Who in the world would asking help and alliance to someone who literally tried to kidnap and rid of your child and obviously want your position?