Published: Apr 19, 2011 3:38 AM EDT
Updated: Apr 19, 2011 12:38 AM EDT

ESTERO, Fla. - The Lee County Sheriff's Office says there is still no sign of Mary Ann Zarb, one full week after she disappeared from her Estero home.

Adding to the mystery is the arrest of four people inside her home Friday.

"I'm frantic.  She's a wonderful person, I don't know what happened," friend Joann Hussander said. 

Neighbors say Zarb moved in alone a few months ago, but was often seen outside with her dog.

Concern for her sudden disappearance grew as four people were found inside her home Friday.

Investigators say Shane Simpkins, Stephen Smutney, Nicole Durden and a 17 year-old girl were arrested.

The sheriff's report says Simpkins was spotted snorting cocaine off the kitchen table.

The connection between Zarb and the four arrested isn't clear from the report.  But friends say Zarb had recently hired at least one person to do remodeling work in her home.

"How there ended up being two men and two women at the time the police were there, I don't know," Hussander said.

So far, deputies aren't saying if there's any connection with Zarb's disappearance.

The four people arrested are out of jail.

Information on Zarb's whereabouts can be called in to Crime Stoppers at 800-780-TIPS.

Family members are offering a $5,000 reward for information about Zarb.