My cat

My cat suddenly didn't like her cat food and I don't know why, so I took her to see a vet. The vet told me :"don't worry, she's fine." But I still worried about her. On In the afternoon, my mother came home and saw/knew my concern/misgivings. She told me, that, in the summer, not only people would eat less because of the heat/sweltering conditions, but also (the) animals. I thought she's right.

Thanks for your reply! I'm an editor working in a school. It's a gravy train* with a low [not much] salary but much a lot of time, so I'd like to continue/go on with my English learning. However, I'm weak in English, so I hope there will be someone who can help me with my writing, just correct my notebook on italki. At first, I supposed that people help someone after they have added each other as a friend. Well, it seems unlike/not like this/my assumption/supposition. Sorry for of my choice of words verbosity, and I don't know if my expression is right or not.
Thank you for your reading！

*not the right expression;  you could say 'It's a dead-end job' [a job with no future prospects]

My cat

My cat suddenly didn't like her cat food and I don't know why, so I took her to see a vet. The vet told me :"don't worry, she's fine." But I still worried about her. On In the afternoon, my mother came home and knew I was worried my misgiving, she told me, in the summer, not only people would eat less because of the heat swelter, but also the animals. I thought she was  though she's right.