The Dynasty star cut the ribbon to the Shooting Star Children’s Hospices boutique in Cobham, Surrey – and donated 300 items from her personal wardrobe.
The 85-year-old, who is patron of the organisation, said it was an “honour” to give away her belongings to help the charity continue its “wonderful work”.
A Montblanc zebra handbag priced at £300, a pair of autographed Donald Pliner shoes, and a pink kaftan designed by her daughter’s brand Maryam and Katy Couture were among items donated by Joan.
Karen Sugarman, the charity’s executive vice president, said it was “exciting” for Cobham to be visited by “such an iconic global star”.
Shooting Star supports 700 children with life-limiting conditions across Surrey and London.