Hi Gerry - the online GRO website indicates mother's maiden name was also Crook.
As indicated by the dash (-) below.
CROOK, EDITH MARIA - (Mother's Maiden Surname)
GRO Reference: 1897 S Quarter in WALLINGFORD Volume 02C Page 329
You can register for free on the GRO website, and that will enable you to view Births (1837-1934, 1984-2020) and Deaths (1837-1957, 1984-2020).
The Births Index provides MMN (mother's maiden name), as well. And if a birth was illegitimate, the dash (-) is present for MMN.
The Deaths Index provides ages at death prior to when they appear on the FreeBMD starting in 1866. So it's worth registering with the online GRO. You don't have to include a credit card number until you order a certificate(s).