I wouldn't dispair picnic, people are very quick to label these days. Obviously I don't know you so I hesitate on giving advice, it is difficult to strangers over the Internet but I would call her a shy child. I have been on another thread about shyness, unfortunately I can't find it ,but 'selective mutism' was thrown in a lot as if the country is full of them, whereas I would say there were very few and loads and loads of shy children.
It is worth asking your GP, but I would on no account take her with you and I would never ever mention her shyness as a problem in front of her. I said earlier that drawing attention to it was the worst thing for me. I am thankful that my mother took a very laid back approach and when teachers asked if I spoke at home said that I never stopped! ( which was true)
Had she made me see professionals I would have really dug my heels in. I hated teachers writing in my report , 'Satin would get more out of her lessons if she took a more active part' and used to think '.........and they think it is that easy they just mention it and I do it!'
Never look to the negatives. Your positives are fantastic! She is 'bubbly, happy and fun'.
She talked to the teacher enough for the teacher to talk for her, she joined in.She may have taken a year to warm up but she joined in group work.And above all she is fiercely independent and wants to do theses things on her own.
That last one is wonderful. She has the basics. She just needs the building blocks. There is no way I would have joined in circle time at 12 yrs old. I never ever once in my school life asked to go to the toilet, I went at break. I was not a selective mute.
Your problem is that you are very close to her, very worried and she doesn't cope without you. You need some help. Whether it is professional help I don't know, it always worth investigating.
I would start with small things. Firstly, if she is the sympathetic sort, tell the Brownie leader. There all sorts of things she could do to help.
Have a group around, play board games where you have to say something like 'I want to buy Mayfair' as part of the game.
Do my things in the open air idea.
Get a other adult to teach her something like knitting where they have to speak to each other. Go out of the room part of the time but pop back.
Have you got any 3 yr old she could curl up with and read a picture book.
Anything with an activity where she can take part in a non threatening way where speech is just a by product.
Lots of adults are shy. If someone starts a thread on here, which they do, saying 'am I odd I have no friends' it fills up in no time with people saying they are the same, have no small talk etc. Many will not go to a toddler group because no one speaks to them and they can't start conversations with strangers in what appears to be cliques. These people are not all selective mutes or on autistic spectrum, they are merely shy. If adults can't do it it is a lot to ask of a 7 yr old!
I was very sad to come back to the thread and find you so depressed. Stick with the positives and work with them. Be pleased with any slight improvement like saying in a shop 'excuse me, can you tell me where the pens are?' You may be surprised at how each small thing adds up.
If I started a thread asking how many posters were shy it would be full in no time! It is common among adults, never mind children.