Until the stray horse showed up last week.
So right there you have a writing prompt. You have a relatively normal occurrence (a stray showing up) with enough twist to make it interesting (strays don't usually come in the form of horses) and an unanswered question (Where did she come from? Why would anyone dump such a sweet little mare?)
Put your imagination to work! Spin the story behind that stray (horse, dog, cat, iguana) that mysteriously showed up at your house. What is the stray's story?