I wouldn't have thought that such important family paintings (as I imagine they would be to Queen Victoria) would have hung in Kensington Palace where she wouldn't have seen them, i.e. the painting of her marriage, Bertie's christening, and his subsequent marriage in 1863. I always imagined them hanging in Buckingham Palace. Thanks for posting this pictures!
Royal art and furnishings have always been moved between royal residences from reign to reign. Some of these pieces may very well have been inside Buckingham Palace in Victoria's time; others may have been commissioned and owned by others (not the Crown) and acquired more recently. During and after Victoria's death, most of the State Rooms fell to disrepair and lay empty and bare (or used only as storerooms).
In the past, collections used to be broken up and split between properties, or pieces given to courtiers or retainers, or sold when it was determined there was too much excess. In the 1920s and 1930s, Queen Mary did much to reassemble collections and display them in a more historically proper way. Today the Royal Collection handles this duty.
I would imagine if you went to the Historic Royal Palaces website section on Kensington Palace, it would tell you some history about the art presently in the palace.
