Artnet shows that a copy of this bust, by Nemon, was for sale by auction at some point. The Worshipful Company of Grocers' website mentions a bust of the Queen Mother, by Nemon, in their Livery Hall, presumably the same bust, or a copy. We don't know if the lady has been taken out for an airing or if the Company has two of her.
Site: Queen Mother - Grocers' Hall (1 memorial)
EC2, Princes Street, Grocers' Hall
The sculpture is in the courtyard/car park of the Grocers' Hall. It's publicly accessible by either of two alleyways off Prince's Street opposite the Bank of England, but closed off at weekends.
This site for their first Hall was acquired by the Grocers in 1427. Today’s is the fifth of the Grocers’ Halls. The fourth survived the Blitz but still burnt down in 1965. The new hall was opened in 1970 by the Queen Mother, an Honorary Freeman of the Company.
Credit for this entry to: Alan Patient of www.plaquesoflondon.co.uk