Updading to 4.0

Hi! I am sorry if this is a 'stupid' question, but I am lacking experience here and be rather cautious ... I#d like to update my Full Frame Pro version to 4.0.. I have created a child theme according to the instructions. When I update the FullFrame Theme to 4.0 will I keep my adjustments etc. due to the child theme? Is there anything I need to consider to not loose the current design of my website? Thanks a lot in advance Thorge