Is energy always conserved?

Hi Physics girl,
Thank you for making such an amazing videos.
I need ur help.
Actually, I had a fight with one of my friend and she is Ph.D. student of Physics.
It is very simple.
As per definition of Pressure, P=F/A
Then she said if P is constant, then F is proportional to A.
I agree with it.
But, then she said if I apply force in one cylinder causing increase in pressure of fluid, it will then apply force on plate kept on water in other connected cylinder. That is true
But then further she said if I increase area of second cylinder, keeping pressure , mass (amount of water) same, it will cause more force on plate.
Do u think is it true?
Cause I agree F is proportional to A keeping pressure constant. But in this case as per me if u keep Pressure constant without adding any further water and increase second cylinder area will increase force required to lift plate (to previous height or above), not the force applied on Plate.
I will be very grateful if you can make video on it.
Thanks :)