“Top Left drawing  
The subject of Discords immortality and Fluttershys Mortality rarely ever arose with the couple. They were happy to have eachother and enjoyed all the time they had together however when Fluttershys first grey hair came Discord suddenly got very serious about it. Her mane greying meant that her time was coming to an end and he wouldn’t have a lot of time left with her. Fluttershy always reassured him that she wasn’t going anytime soon.
 
Top Right Drawing (Head canon warning)  
In her later years Fluttershy started to notice her body.. changing. The fluff around her chest was getting fluffier her irises seemed to be a little different but she would always shrug it off that was until the day she woke up and her hoof wasn’t a hoof anymore. Turns out 40+ years of Chaos Magic from both the Lord of Chaos and their three charming little hellraisers can effect the average pony, it doesn’t help that at this point in her life she had ‘accidentally’ been turned into a Draconequus nearly 12 times mostly thanks to her children not being able to control their magic.
 
Bottom Drawing  
During her lifetime Fluttershy was turned into a Draconequus a lot. It was mostly her childrens fault and one time she was assisting Twilight with something and well its kinda went wrong. The first time it happened near Everypony freaked out, her friends didn’t know what to do, Mirage was just a foal when it happened so she didn’t really know what was happening and Discord was a mixture of surprised and elated “