One of my cats died on Monday as she was put to sleep?

due to liver problems. Today, her mother had a stoke which induced her to have an epileptic fit she never recovered from. Would this have been from the stress from losing her daughter or did she die on purpose to be with her (give up)? Some people say that animals know when they and other animals are dying. I am glad I spent my last day with her today cuddling with her purring.