I'm with you OP.
5 year old being confused/frustrated with classmates.
Very typical of a bright five year old - they can't see why classmates don't get things they find easy to understand.
Doesn't mean she has social needs at all - pop her into a group of 7/8/9 year olds they will be able to converse with her on her level.
5 year old with high reading levels.
Lots of messages on MN where parents battle to get the right level reading books for children - give up the fight, abandoned the school reading scheme, bin the reading record book and buy/borrow from the libary your own progressive reading scheme and tonnes of excellent books.
Maths level 1b
This isn't a particularly high level for Y1 - teacher should easily be able to differentiate for this.
Doing higher level maths at home - two possibles here either she is going off and learning by herself (some love to plough through maths text books as bed-time reading) or she is being guided to worksheets/books/games that extend her (lets call this scaffolding her knowledge).
Encourage either approach. Print-off NC levels and have a little test with her each fortnight to see what level she is at. When the level reaches 2c / b for a Year1 the teacher will be looking to more to either maths in with the year 3 class.
The part about her not being able to concentrate with lots of noise is a complete red herring in my view - most maths lessons require children are quiet when recieving in-put (ie being shown a new technique) then the noise and disruption levels rise as the children head off to work in pairs or small groups - your girl could do her work in a quite place in school, the libary for example.
Bear in mind there will be a lot less noise and disruption from year three and four classes, so it would only be that her noise concerns are accomodated for a short while (not the next two years - she'll be demonstrating a secure 2c/b by next spring)