Ghostly Hardbodies — Julia Derek

Having solved a second murder with Lennie the ghost in a matter of days, Celeste Jones decides she needs a timeout or she'll have a nervous breakdown. For now, she'll focus all her attention on getting Six-Packs, her gym, off the ground and getting back in shape after eating far too many donuts. Lennie will just have to wait to move on to the afterworld. He must solve five murders for that to happen.
Unfortunately, Celeste's peace and calm only lasts for a couple of weeks. That's when Lennie discovers information that leads him to believe a Six-Packs gym member who committed suicide a year ago may in fact have been murdered. Despite being determined to focus on the gym business and minimizing her growing butt, Celeste can't resist trying to solve the mystery surrounding the member's death. Well, it's not like Lennie is giving her much choice, either...

NOTE: GHOSTLY HARDBODIES is a stand-alone cozy murder mystery for people who like to laugh. You DO NOT have to read the books in order, as each mystery stands on its own.