Walk Right Back by Daryn Cross

A walk-in angel battles deadly demons to save very special twins. In a soul exchange, Miranda, a walk-in angel, wakes up on a beach while being given mouth-to-mouth resuscitation. She discovers she's been zapped out of the body of a dying eighty-two year old woman into the body of a thirty-four year-old wealthy woman who planned to drown in the ocean and leave her life of misery after being jilted by a lover. Miranda discovers from her replacement guardian that she is there to save her friend, Olivia, and Olivia's twins from demons who have vowed revenge for sending Keara and Heinrich to long sentences in Hell. But, there's one catch. Miranda's former lover, Jared, whom she swears she'll never forgive, is also there incarnate. He has vowed to stay away from her unless she invites his advances and tells him she loves him. Once Miranda is united with Olivia and Gregory and the rest of the former earth angels, they set out to battle a host of new demons led by Kendra, Keara...