Manigault, 39, began her romance with O'Neil, 36, about a year after the death of her fiance, Michael Clarke Duncan. Duncan died in July 2012 nearly two months after suffering a heart attack.
"She's been really apprehensive about dating since Michael died," a source told People.com.
"But everyone who loves her has been encouraging her to step out and try it again. So far, things seem to be going good. They seem really happy together."