What does Matthew 9:21 mean?

A man named Jairus is leading Jesus and His disciples to help Jairus's daughter, who has died. They are packed in on every side by a "great crowd" (Mark 5:24). Suddenly, a woman touches Jesus' cloak—not grabbing or twisting, but merely making contact (Matthew 9:20). She has suffered from a discharge of blood for 12 years. This was likely an abnormal menstrual discharge, meaning not only is the woman anemic and weak, but has also been ceremonially unclean within the Jewish community for a dozen years.

This verse explains why she pushed through the crowd to touch Jesus' garment, risking being caught in violation of keeping her distance from others, as the law required. She believes. She has heard of Jesus' healings and His power and is convinced that she will be healed by just touching His cloak. She doesn't dare to be so forward as to come to Him directly and kneel before Him and make the request. As an unclean woman, this would likely have been quite inappropriate. Instead, she has devised a way for Him to heal her, she likely hopes, without ever even being noticed.

Jesus, of course, notices.