hi pnance

sorry you're feeling this frustration. maybe you can consider this, my suggesion...it requires a lot of extreme patience.

from free-feed, "how much does she usually eat each a day" amount, reduce about a half cup every other day and so on..until the exact amount you've tried before.

or this second suggestion, just hand out the exact amount like you did and be firm, tough. pretend you don't hear her meows or see her faces. but do pet, give a plenty of attention (out of kitchen/a room away from kitchen definitely where she eats her meals). maybe to reinforce her more, give two treats after her meal every other day to 2 times a week and so on....so she'd not demand.

afterall with long progress, I believe she should be fine. hopefully time goes fast and by a few months, she's not over-weight as you wished. lucks sent on whatever you do!