Sorry if this is not in the correct forum, but I am dizzy from going around the houses with the UK Border Agency? Is that place ever going to be functional?

My sister lives in NZ and is coming back for her 50th birthday, travelling on a UK passport. Her daughter (13) will be travelling on a NZ passport. Can they present together in the UK queue at the LHR border? No one seems to be able to tell me so if anyone can help, FT can

Thanks very much in advance.