Manchester City WFC are the current FA Women's Super League 1 champions and FA WSL Continental Cup holders.
The 22-year-old has been with Blues Ladies since 2013, following a short spell at Bristol Academy WFC.
During her time with the Club she has made a total of 86 appearances and was part of the Blues squad that reached the UEFA Champions League semi-final in 2014.
On the national stage, she has also progressed through the England youth ranks, and was recently been selected as part of the England ‘Next Generation’ Squad.
Blues Ladies Manager Marc Skinner said: "I would like to personally thank Mel for her services to the Club and wish her well in her new venture.
"Mel is a great example of how taking a chance on a young promising player can pay dividends in the future.
"We continue to look forward to helping all of our players on their personal football journeys."
Everyone at Birmingham City Ladies FC wishes to thank Mel for her commitment over the past four seasons and wishes her the very best of luck in the next chapter of her career.