I felt the need to poke around at something this afternoon, and since I am descended from Carters of Wellingborough ...

From the other thread, Trish 1120 posted (with my additions and deletions):
Roy WHITING.... Mothers name CARTER
born 16 Dec 1929, died 1990 Wellingborough
___ WHITING... Mothers name Carter
younger son who appears not to have died by 2006
Marriage:
Catherine M CARTER + Gilbert WHITING
September 1929
Wellingbro' 3b 412
Birth:
Catherine CARTER
March 1907
Mt Harbro' 7a 12
Also, there is confusion about Emily Palmer's mother being Mary or Emma, and that is because, as noted above in this thread, her mother Mary had died by the 1901 census:
Mary Palmer, age 39
mar qtr 1899
Wellingbro 3b 100
and father Henry shows as having wife Emma (born c1861, Leicester); there isn't actually a matching marriage. That Emma is not Emily's mother; she is her stepmother. Although ... the personal details (date and place of birth) for Mary and Emma do match ... But there is no other Mary Palmer in 1891 who fits that death.
The birth posted for Catherine ("Kitty"?) Carter looks to be the best bet, and the only way to confirm who her parents were (or at least her mother) is to get the birth certificate; her marriage certificate to Gilbert Whiting should also be got, to check against the birth certificate for age and to see whether she named a father, and if so, who.
There is no death registration for a Cat* or Kat* or Kit* Whiting (or Carter) born 1906-7 that seems at all likely to be her. Nor is there any likely remarriage for any version of the name. Gilbert Whiting born 23 Dec 1908 died in 1995 in Wellingborough.
I haven't made any more headway on where Kitty emerged from, since I can't find her or Emily in 1911 either (I'm suspecting they will be there under the surname of a husband/partner of Emily, but no luck so far).
If you do get the 1907 birth certificate, just so we know we're barking up the right tree, I'd be happy to look some more, just in case Kitty and I are cousins.

My Carter is a great-grandparent born abt 1860 in Rushden, whose child, my grandparent, was born and married in Wellingborough. Of course, there were gazillions of Carters in Wellingborough, and my great-grandparent's generation was a little old to include the father of someone born in 1907 whose mother was born in 1890.
Actually ... I see a Ralph Carter, about the only male Carter in Wellingborough who would be about the right age (in 1901 he was in Rushden, born abt 1889 in Yelden, Bedfordshire) -- whose occupation was the same as Henry Palmer's ... If he was the daddy, we likely aren't related; but we won't know unless Kitty's birth or marriage certificate names a father.