http://www.mangago.me/read-manga/the_evil_lady_s_hero/ one that I like ٩(๑❛ᴗ❛๑)۶ the female lead is not physically strong but she is mature and more cool-headed than most.
http://www.mangago.me/home/mangalist/943244/ actually I made this for my friend, but I think it's what you're looking for

Hey, I hope you are having a great day. I have been struggling a bit. I've seen all these princess love stories things everywhere and I want to try one out. I just don't know where do start. Can you give me some really good ones that have a strong female lead?
Thank you