You want to take a child across international borders and in to the UK.
We have to be mindful that in addition to the basic visitor rules expressed in Appendix v, that Parliament has also instructed the Border Force to be alert and act as preliminary enforcers for the Children Act 2004. This is an additional responsibility over and above protecting our borders and invites additional scrutiny. The Border Force has taken this responsibility seriously and can be quite aggressive about it.
People who are unaware of this responsibility can find the extra diligence invasive and even insulting. Brits travelling with children can become especially upset; they can get angry and post hot takes on the net.
I have the judge's permit to take her to the UK but do I need to have
these documents translated?
This document should be
- translated to English; and
- have an apostille affixed to it.
Maybe they will ask for the apostille or they may require you to get one whilst in the UK. Or maybe they will trust you. I always advise people to play everything strictly by the book and avoid problems. You should also have an apostille of the child's birth certificate. The child's maintenance and care during their visit in the EEA should be documented, they can get you for that also because some of their responsibilities are handed down from Brussels.
For more background, read ILPA's Fact Sheet: Children: New Statutory Duty.
Disclaimer: I am a member of ILPA.
Anecdote from the thread linked to above (posted by user47663)
I have twice been questioned upon arriving back in Britain from
France, although both times was allowed through. My son (aged 8) and I
are both British, fair haired and look alike. Last time the passport
control officer simply asked him "Who is this lady?" and was satisfied
when he said Mummy. However I saw another mother and young daughter at
the booth next to me getting a considerably harder time, and indeed I
was less sympathetically treated the year before, until a supervisor
decided my son looked 'comfortable' with me. This year I am taking his
birth certificate, irritating though it is, especially as I had to
produce it to apply for his passport in the first place! I also
pointed out that I had not been advised that I should carry his birth
certificate when I received his passport, only when I arrived at
border control (which was a tad too late).