A woman this afflicted is ritually unclean in those days. She was not supposed to be with the crowds. Thus we have to go lady how people see us to receive our breakthrough.
The woman had to feel that she deserved the healing. Many people believe that whatever affliction they have is a punishment and well deserved. God's healing grace will have trouble flowing with that type of mindset.
Though the woman was desperate to be healed, she was humble in her request. She only touched Jesus' garment at the lowest possible part. She could have touched His sleeve, His back or His waist instead. We aren't entitled to anything in this world. We are gifted with God's love and mercy and have received entry as God's children through Jesus' death on the cross.
"If only I..."
Faith moves God's heart in ways no other thing can. This woman believed something her heart told her was possible. Many times we silence our hearts as they say such incredulous things. We must listen for God's still small voice is there and grows louder every time we pay attention to it.
Jesus knew that power left Him. He ultimately knew who touched Him and what the woman was up but Jesus wanted to teach us something by asking "who?". By asking "who?" We see that it seemed like it was the woman who forcibly took her healing and not God. (We know of course that it's God's urging that brought this woman to Him.)
In asking "who?" the woman had to speak up! She who was shunned by society had to come out into the open and confess. She did! She spoke out and glorified God through her testimony. Jesus wants us to share what He has done for us! He wants out faith to move His heart! He wants our faith to move the mountains in our lives!