[If she loves you, she shows it by making an effort to make you happy.]
That’s true, but it’s a two way street. A ‘giver’ finally stops giving when they receive nothing in return.
You notice the last part of my post was "(and yes, it works in the other direction too)".
A relationship works when each party values what they get from the other, and considers the cost of keeping the other happy to be more than worth the benefit they get from the work the other person performs to make them happy.
A relationship is in deep trouble when one or both parties decides it's too much work to keep the other happy.