I cannot do the whole letter for you as I am not expert with the script - but I think it is a letter from your gt.grandmother, not grandfather. The signature "Witwe Gustav Peters" means (The) Widow (of) Gustav Peters. Obviously this will be clearer if someone tells you the full text.
The Memorial Card:
"The Souls of the Righteous are in the Hands of God: the torment of death worries them not; they are at peace". Proverbs 3.1
In loving memory of the well-respected Mrs. (Widow) Gustav Peters, formerly Hausmann, nee Burbach, who fell asleep in the Love of the Lord at about 11.30 in the evening of 14th February, 1922 in Dormagen after a short, serious illness borne with patience and courage.
The departed was born on the 19th January, 1863 in Dormagen and married Heinrich Hausman on the 11th November, 1882, with whom she lived in a happy marriage until his death. She contracted a second happy marriage with Gustav Peters on the 5th September,1896 but he also preceded her into Eternity.
The departed always strived to fulfill her duties as wife and mother according to Christ's teachings. After the deaths of both her husbands she dedicated herself to the care of her children. In the fulfilment of her religious duties she always set them a good example. She bore her serious illness which struck her suddenly and unexpectedly, with patience and fortitude as the Will of God.
Prepared by the receiving of the Holy Last Rites she gave her soul back to her Creator. To her children the departure of the good, faithful and loving Mother is an irreplacable loss. They, as well as all who knew her, will always remember her with love, in the hope that the Heavenly Father will reward her for her incomparable devotion.
Four daughters, four sons, two daughters-in-law, four sons-in-law, five grandchildren, five sisters and other relatives mourn at her graveside. They ask the Priests and the Faithful to remember her in their prayers so she will rest in Eternal Peace.