House one left protected by two little boys and a girl (5,6)

'house' is the definition.
(I know that royal family is a type of house)

'one left protected by two little boys and a girl' is the wordplay.
I cannot really see how this works, but
'one' could be 'i' (Roman numeral) and 'i' is present in the answer.
'left' could be 'al' (I've seen this in other clues) and 'al' is located in the answer.
'little' could be 'l' (abbreviation for little) and 'l' is located in the answer.
'a' is found in the answer.
This explanation may well be incorrect...