Hi Shoshannah
WW11 relocated thousands of people, men & women, and 13 was very young to have left home around 1932, unless she went into service or to live with another relative. At that also means about 7 years before the war began, where she could have been living anywhere
If you go on the freebmd site and put in "G W, search all districts and counties and years from 1939 to end of 1945 for marriages " you will find that about 25 entries come up.
Only 3 of them have the middle initial of "E", so one of them could be your G. None of the marriages were in Cambs.
But she could also have not given her middle name to the Registrar, so be one of the plain Gladys Winter.
She may have also moved to the USA at the end of the war as a War Bride.
It may be that you have to buy at least one of the Gladys E marriage certs and hope that your first choice is the correct one.
I do have 2 family members who married servicemen in England , one in in the Great War ( from Canada) and one in WW11 from the USA, and both show details of where the men were billeted, father's names etc.
Hope this helps, and sorry to be a bit negative, unfortunately the English 1921 census isn't available yet to try and find her whereabouts on that