It happened around 1 p.m. on July 11 at the Marshall's on Trooper Road in West Norriton Township, when two women approached the 76-year-old victim.
Police say the shorter of the pair opened her purse to flash a semi-automatic weapon as they told the woman they'd kill her family if she screamed.
While sitting in the victim's car, they discussed her ability to withdraw thousands of dollars from her bank accounts and revealed they knew where she and other family members lived.
They even knew her husband was working in the yard that afternoon.
After about an hour, they forced her to drive with a gun pressed to her ribs to her bank on Egypt Road in Lower Providence, where she withdrew $1,500. After that, they had her drive back to West Norriton to the Home Depot, where they took her cash and jewelry.
Anyone with information is asked to contact Detective Mark Wassmer at mwassmer@wntwp.com.