We don't know much about their dear lady. She didn't even get a full chapter about what she did. When you look at her story it wasn't until she died that we find out about her good works and charity. Doesn't seem like much but from God's point of view it was more than enough.
Sure this story is about the power of the Holy Spirit and Peter being available to the moving of the Spirit. It is also about Peter serving the church in Joppa. Yet the bigger story is Dorcas.
We know from the story that she was a seamstress. She made clothes and looked after the widows. Those at the church in Joppa loved her and were distressed at her passing.
They had followed the Jewish tradition in preparing her body after death. They sent men to neighboring Lydda to get Peter. When Peter came and saw what she had done for the widows he took the time to seek God. Then he raised her from the dead.
Through her death and resurrection Dorcas even served God. Many in Joppa that knew her and were not Christians came to know the Lord because of her story.
Perhaps when Peter shared with the other disciples what had happened it stuck in James' mind as he wrote, "Religion that is pure and undefiled before God, the Father, is this: to visit orphans and widows in their affliction, and to keep oneself unstained from the world." (James 1:27 ESV)
This could be why her story was important to God. She was serving and being His hands to the widows.