Hi Cliff,
Debra Anderson is the original recording and it is by Debra Anderson.
Her original was played as a fairly new release at the Mecca (74).
I've always believed the Dee Dee Schwarz/Warwick to be a cover, fairly soon after the original (a couple of months or so).
Personally, I prefer the Dee Dee, but theres not much between 'em!
Worth noting that, the Dee Dee Warwick also came out twice on Private stock, originally in 74 on 45,011 as DEE DEE and then in 75 on 45,033 as DEDE.
I also have the original UK copy I bought when new!
Like it!
Sean