Thank you for the responses. You confirmed what I thought. I'll see about contacting her family.
Shirl4146 I do believe that the copyright does still exist unless you have received a release from the family. Copyrights used to exist for at least 7 years after a person's death. I do believe that Congress passed a law increasing the time to something like 70 years (not sure on the length of time).
Yes, it's still a no no. The property is now owned by her estate. They could give you permission if you know how to contact them.
Why don't you start with asking the family? They will most likely be pleased that her designs are still in demand.