Having begun her career with Gillingham, Cooper previously helped Brighton & Hove Albion achieve promotion to FA WSL 2, and she is also a talented cricketer having represented England at Academy level.
Cooper, who joins the squad in Portugal for this week’s warm-weather training, told chelseafc.com: ‘It is a dream of mine to join a pro club so to be here is an amazing feeling. I have worked my way through the football ranks and am delighted to have done enough to earn a contract with Chelsea.
‘I got invited for a two-day trial here and was ecstatic with that, but after two days they asked me to say a bit longer so Emma could have more of a look at me and after that they offered me a contract!
‘I must admit I had a little cry as I had given everything to earn it and was delighted that my efforts were being rewarded.
‘Emma has told me she likes my attitude and while I have some things to work on she said if I keep working hard, as I did in the trial, there is no reason I can’t challenge for a place in the team.’
The centre-back scored in London Bees’ shock win over the Blues in last season’s Continental Cup and Hayes believes she has the talent needed.
‘Deanna is a player who performed so well when London Bees beat us last year and hasn’t looked out of place during her time training with us,’ she said.
‘She has taken her opportunity with both hands and is desperate to get her opportunity and now she has got it. She is an excellent one-v-one defender and can play all the way across the back line which adds depth to our squad.’
Photo – chelseafc.com