How can I get help for my 95 yo mother to hear me on the phone. I live away, won't get hearing aides. Is there a phone that helps hearing?

My mother lives in Resthaven Mt. Gambier. She is 95 y.o. I live in Adelaide I ring her often but she cannot hear me. She gets upset she can’t hear. Won't hear of hearing aides. I was wondering if Telecom has special phones that amplify the sound louder? She is very unwell at the moment. I phoned my brother down there he said this Christmas will be her last. I hope there can be something out there that can help. Thank you -Sharon