The singer is past the half-way mark and is "anxiously awaiting" her little girl's arrival, she tells PEOPLE exclusively

It’s going to be a busy summer for Kimberly Caldwell.

The American Idol alum is set to welcome a little girl in the fall, and she and husband Jordan Harvey — who are both “anxiously awaiting her arrival” — have been “putting the final touches on her nursery,” she tells PEOPLE exclusively.

Showing off her sweet pregnancy look in a new photo, the singer, 33, says she’s also “looking forward to keeping up with my growing baby bump in style” this summer.

“We are finally past the halfway mark at 21 weeks, and Baby Harlow is wiggling around like crazy,” adds the mom-to-be.

Caldwell told PEOPLE in May that she was expecting her first child, a daughter the couple have already named Harlow Monroe.

Kimberly Caldwell pregnant daughter baby bump

Kimberly Caldwell

— Melody Chiu