Her strength is not only her physical ability, but also mental force, moral courage, power of reason as well as resource and authority. These are all traits that are enlightened by God. Her authority comes through Jesus Christ. Only through her relationship with the Lord can all of these attributes be fulfilled to their true potential. It is through her strength in Him that she is known by this strength.
Her dignity is her proof of character, how she conducts herself and responds to the world around her inside and outside of the household. This entire passage is a testimony to her character. She is defined by her noble character and her strength in the Lord.
Fear is an emotion many people struggle with to a lesser or a greater degree. The wife of noble character, however, laughs without fear of the future. This is the result that her noble character and her strong relationship with the Lord grant her.
Psalm 27:1 -- "The Lord is my light and my salvation— so why should I be afraid? The Lord is my fortress, protecting me from danger, so why should I tremble"
If we put our trust in the Lord, wholeheartedly, then there is no worry because God has it covered. It is only our doubt that causes us fear. The enemy wants us to be afraid because it increases our doubt in God. However, the Lord is my light and my protector -- He will guide and guard us through the roller coaster of ups and downs we call life.
The wife of noble character knows these truths about the Lord, thus she is not afraid of the future, nor should we be. It is her trust in God that allows her to show her strength and confide in her character. She knows that God will guide and guard her through all things. Without fear, she can laugh at the enemy and be a shinning light for all others to know God more fully through her.