YPSILANTI, Mich. -

Tonya Jackson last was seen Saturday night at a Romulus hotel near Detroit Metro Airport.

Her family hasn't heard from her since that day. They are growing increasingly worried she may be the victim of foul play.

It appears Jackson, with four children and her husband at home in Ypsilanti, decided to have a date with another man.

"It's suspicious," said her sister, Nikeyta Evans. "We have actually been out looking for her, too. We have been riding around, searching different hotels, parking lots, to see maybe if she got a room."

Washtenaw County Sheriff's deputies also are concerned. They first heard about it on Monday. Spokesman Derek Jackson said there are more questions than answers at this point.

"It's not something that Miss Jackson has been known to do in the past. This isn't typical behavior for her. She did have a young daughter who she was supposed to pick up and she never made it, actually, to pick that daughter up," he said. "So right there are some key indicators that something may be wrong."

Tonya Jackson apparently set up her liaison with another man using a woman friend of hers. Sheriff's deputies have spoken with that woman and the man she met. Both have been cooperative with law enforcement.

No one knows what happened to her.

Her family clings to the hope that she just needed a break. However, not showing up for her housekeeping job this week is another example of unusual behavior and possible trouble.

"I'm at the point that I don't care about whatever is going on in their relationship. They'll handle that. We just, the family, we want to know that she's safe. Even if she's somewhere and she just don't want to come home, call somebody and let us know that she's OK," said Evans.

Tonya Jackson, 42, stands 5 feet 7 inches and weighs about 180 pounds. She has brown eyes. She was driving a silver 2007 Saab 9-7x with Michigan license plate CCL 7888.

Anyone with information on her whereabouts is asked to call the Washtenaw County Sheriff's Office's Confidential Tip Line at 734-973-7711.