Where is the line between helping occasionally and enabling, or getting taken advantage of?

I admit I’m a sucker for a sad story but I have firm boundaries like no one moves into our home, or no cash given but I will pay a bill directly or buy product. My mother is far nicer than me and let’s people stay over in her basement, take showers and do laundry.

But sometimes I feel repeated help is hurting the person because they ‘depend’ on me instead of hustling. Where is that line for you? Why do I sometimes feel taken advantage of instead of being grateful I can help?