I recommend "The Tough and Pretty Elder Sister" to you. The female protagonist, Jiang Hehua, was a merchant's daughter before her rebirth. After her rebirth, she became the eldest daughter of the Jiang family, who had nothing to her name. However, her father and grandmother are very kind and upright, which is exactly what you described. The story in the book is very warm and relaxing, suitable for the type of ancient language rebirth that you are looking for. I hope you like this fairy's recommendation. Muah ~๐