Visiting the UK--which line at airport?

I am a US/UK dual national and my gf is a US citizen.   We are going to the UK just for a one-week visit at the end of March.  I plan to enter on my UK passport.  My plan is to go through immigration with my gf, in the visitors line.  After all, there's no point my going in the faster UK line if I just have to wait for her.

My question is whether this might raise any questions.  If the officer sees that my gf is coming to the UK with a UK citizen, will it raise any doubts about how long she plans to stay?  I know people have had problems when coming to visit a UK s.o., which makes me wonder if visiting with a UK s.o. might cause similar problems.  Any thoughts?

I would not recommend going through the visitors queue with your UK passport.  The IO will not be happy and may tell you to go UK/EU queue.

I'd have her go through the UK citizen line with you-when we arrived we asked them what we should do and that's what they told us.

There is someone stationed there before the lines start-best to ask them when you arrive.

I'd have her go through the UK citizen line with you-when we arrived we asked them what we should do and that's what they told us.

This will just be a one-week visit.  She doesn't have any kind of visa.

I'm trying to remember what my family would do when we used to go over for vacation--my mom had her UK passport and all of the rest of us were on our US ones.  I guess I will just ask my mom to see if she remembers.