Wikipedia has a
copy of the marriage certificate of Princess Elizabeth and the Duke of Edinburgh .
If I read it correctly, the signatures of the witnesses seem to be as follows:
1) King George VI: George R
2) Queen Elizabeth (later The Queen Mother): Elizabeth R
3) Queen Mary: Mary R
4) Prince Philip's mother: Alice, Princess Andrew of Greece
5) Princess Margaret: Margaret
6) Prince Henry, Duke of Gloucester: Henry
7) The Duchess of Gloucester: Alice
8) Princess Marina, Duchess of Kent: Marina
9) Lady Patricia Ramsay: Patricia Ramsay
8) Sir Alexander Ramsay: Alexander Ramsay (?)
9) Princess Alice, Countess of Athlone: Alice Mary
10) The Earl of Athlone: Athlone
11) Victoria, Marchioness of Milford Haven: Victoria Milford Haven
12) The Marchioness of Milford Haven: Nadjeda (?) Milford Haven
13) The Archbishop of Canterbury: Geoffrey Cantuar
14) The Dean of Westminster: Alan C. Don Dean
15) The Countess Mountbatten of Burma: Edwina Mountbatten of Burma
16) The Earl Mountbatten of Burma: Mountbatten of Burma
17) King Haakon VII of Norway: Haakon R
18) King Michael I if Romania: Michael R
19) Ingrid, Queen Consort of Denmark: Ingrid (?)
20) King Frederik IX of Denmark: Frederik R
The bride and groom, identified as "Philip Mountbatten" and "Elizabeth Alexandra Mary Windsor" signed respectively "Philip" and "Elizabeth", rank or profession: "H.R.H. The Duke of Edinburgh K.G" and "Princess of the United Kingdom of Great Britain and Ireland".
The bride's father is recorded as "Albert Frederick Arthur George Windsor", rank or profession: "H.M. King George VI of the United Kingdom of Great Britain and Ireland and of the British Dominions beyond the Seas; Defender of the Faith".
It is quite interesting actually.