(WEST PALM BEACH, Fla.) -- The daughters of a missing Florida school nurse made a tearful plea for help to find their mother, who mysteriously went missing earlier this week without a trace. Kimberly Lindsey, 49, texted one of her daughters Sunday to let them know she returned home from a trip, but she never showed up for work at Bak Middle School of the Arts in West Palm Beach on Monday.
"The minute she didn't walk through the door I knew that I needed to find out because she did not contact me and I would have been the first person she would have contacted," said Roberta Azrak, Lindsey's friend and co-worker.
School officials reported her missing on Monday and deputies conducted a welfare check at her Palm Beach Gardens home. They found her vehicle and personal items in the home.
Lindsey's three daughters -- Sarah, 20, Sophia, 18, and Savannah 16 -- are holding out hope that she will be found alive.
"It's heartbreaking to be away from her. It's harder than anything that we've ever been through and it's really scary not knowing what's happening and we will do anything to bring her home," Sarah Lindsey told ABC News.
At the press conference Thursday, Sarah's voice cracked as she described her mother as a "self-made, independent woman," who was a "nurturing" and a "loving" mother.
"Memorize her face. Keep her in your head. Look for her. Do anything you can," she said.
The family has set up a Facebook page, "Find Kim Lindsey," to aid in the search and handed out hundreds of fliers.
"Share her photos. Share anything you have plus the flier we have and just keep looking until we find her," Sophia Lindsey said.
Kimberly Lindsey, according to her daughters, was last seen wearing a green T-shirt with the words "Explore," "Dream," and "Discover" written on the back.
Investigators are offering a $1,000 reward for information in the case.
"We believe she's endangered," said sheriff's spokeswoman Teri Barbera. "We're very concerned for her well-being."
Copyright 2013 ABC News Radio