The 18-year-old joins from Bristol Academy ahead of the start of the 2013 FA Women’s Super League campaign.
Originally from Kidderminster, Lawley began her playing career at Arsenal Ladies where she gained UEFA Women’s Champions League experience.
She has progressed through the Three Lions ranks and was recently included in the England U19 squad for the Ten Nation Tournament in La Manga next month.
Commenting on the acquisition of Lawley, Blues Ladies boss David Parker said: “Mel is a player I’ve been tracking for some time and have been well aware of her development over the last four years.
“Having joined Bristol Academy last season from Arsenal, she was one of the youngest players in the league and made a significant contribution to their season.
“Mel already has great experience for such a young age, making her debut for Arsenal at the age of 17 in the UEFA Women’s Champions League and has featured heavily for England at the U15, U17 and U19 age groups.
“She will be a great asset this season to have with her versatility to play on either wing, her pace and trickery. But what impressed me the most was her maturity and ability to step up to the demands of the Super League so quickly at just 18-years-old.
“Adding Mel to the group of players we have already signed this winter in Kirsty Linnett and Katie Wilkinson, plus the progression of our Centre of Excellence girls in Coral Haines and Hannah George, it demonstrates not only our vision for the future but the immediate impact these girls can make this season.
“It’s an exciting place to be right now with the blend of experienced internationals and younger players all ready to make their mark this season and I can’t wait to get started with the FA Cup 5th Round just weeks away.”