Hello
A free search of
www.scotlandspeople.gov.uk brings up only one Helen Watt Pryde death in Scotland from 1855 to 2006.
I did the SP search following finding an obituary on Google from Jan 25 1955 in the Glasgow Herald for a Helen Watt Renfrew - wife of Walter Pryde. (If you search using G for Helen Watt Pryde - using 'web' the 5th result will give you the info below).
Possibly the lady you're looking for. It used to be and still is as far as I know, common for a married lady to have her maiden name on either an obituary or gravestone.
I've png'd the image, but it's too big to upload. If you pm me your e-mail address or do the same search as me.
Regards, Steve

The obituary reads:
" PRYDE. - At 11 Gloucester Place, Edinburgh, on 23rd January, 1955. Helen Watt Renfrew, dear wife of Walter Pryde and beloved sister of Catherine Renfrew. - Funeral to-morrow (Wednesday) to Liberton cemetery, Edinburgh; friends desiring to attend please meet at cemetery gate at 3.15 p.m."
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A free search on the ppv site
www.scotlandspeople.gov.uk brings up only one birth in Scotlands between 1855 and 2006 for a Helen Watt Renfrew. Born in 1902. Married in 1931
Her birth entry - available to download for £1.20 from Scotlands People (min spend £6.00) will give her full d.o.b, place of birth, parents names and occupations and mothers maiden name - and date and place of parents marriage.
Marriage entry - will give both occupations and addresses and parents names. £.1.20 to download