Does she have her own number.
Historically the palaces she lived in would have telephones that were manned by her staff.
But a mobile phone is a personal device with a unique number.
Does she have this?
She was photographed using one a while ago.
The last Queen of England died in 1714 and had not bend that title since 1707. So I would guess, no.
It has been reported numerous times that she does indeed have her own mobile. She apparently still prefers to use a landline though when she is at home.
I would think mi 5 and 6 would have that thing so encrypted that you couldn’t prove it existed ………
There’s a scene in the movie The Queen in which she uses a mobile phone (and, yeah, that’s not a proof that she does use one).
It has been said that she has a We-phone.
At a Palace garden party, a Birmingham businessman was nervously speaking to the Queen when his mobile phone rang inside his breast pocket. Conversation died as the “Mexican Hat Dance” warbled on. “Why don’t you answer that?” the Queen dryly asked her mortified subject. “It might be someone important.”
https://www.independent.co.uk/news/people/profiles/the-queen-majesty-and-modesty-6358787.html
One is not amused…
I got rid of my landline four years ago but I still prefer them for talking. You can hear your own voice through the handset, so you don’t shout as much. Plus, the handset is easier to hold, and it doesn’t get hot against your ear like a mobile phone. It’s also easier to do things on your mobile phone if you’re not also trying to talk/listen to it at the same time. 
Thanks for clarifying. We were all very confused about the intent of the OP.
Unless the only people she can talk to also have phones that are similarly encrypted/decrypted, such a phone would not be of much use or very secure.
And I’m curious about whether the queen has a need to know many state secrets. Do members of Her Majesty’s government or armed forces run battle plans by her for her advice?
She’s privy to a lot of government secrets, but one has the impression she can be relied on to be discreet. Anyway, a lot of it will be stuff that only needs to be secret for a while and will probably be on paper anyway.
On the other hand we know there are plenty of journalists anxious to get hold of any but of tittle-tattle, and none too cautious about how they get it. Not to mention the ill-intentioned who might be interested to know, say, her travel plans.
We saw what you did there. 
She gets to see all Cabinet papers, at any rate.
Moderator Note
While “Queen of England” may not be her correct title, this comes across as a bit of jerkish nitpicking. It’s fairly obvious who was being referenced in the OP.
It’s a little unreasonable to think that someone should refer to her on a message board as “Queen of the United Kingdom of Great Britain and Northern Ireland and of her other realms and territories” (hopefully I googled the right title) instead of just referring to her informally as the “Queen of England.”
Let’s stop the nitpicking hijack, please.
From comments in interviews by her grandsons Prince William & Harry, it’s clear that she does have a personal cell phone, and does use it.
But it seems to be mainly for personal use – to her family & close friends. For issues of state – government secrets – she would use landlines at her office in the Palace, or would see the relevant government or military officials face-to-face.
Hmm, I can see what you’re saying but to a Scot, ‘Queen of England’ might offend.
Moderator Note
There is a thread in ATMB on this issue. Please take any further discussion of the term there. Let’s stick to the actual question in the OP.
Colibri
General Questions Moderator