Was it wrong of my boss to do this?

I work a babysitting job. Two kids. I make $60 a week. Yesterday I worked until 7 and I hadn't been feeling well all day. My face was warm and I was a bit fatigued. I didn't mind working though since I have rare late days. My boss always keeps her apartment quite warm so I turned down the AC on to at least 70F and it's usually sitting on at least 80. I forgot to adjust back to what she has to. She texted me a few minutes ago saying this " My husband and I can't afford a bill higher than 150 anything above that so I'm going to have to cut your pay. I'm sorry but we are on a really tight budget. Please in the future I ask the thermostat doesn't get moved. " I understand the problem from her side, having a tight budget and problems with bills but everyone around me, including myself believes I don't get paid nearly enough for working 5 days a week for $60. So my pay getting cut for doing something I didn't think would cause much harm is upsetting to me since I have my own struggles even. Is it wrong of me to be upset in any way about this or am I just having karma? If you've taken care of kids, what is your opinion on this job in general? Thanks for answering.