My son is 8 years old and I teach him piano he is currently grade 5 and he has been learning cello at school since last Sept. He is currently working on grade 3 cello. I suspected over the past year he may have perfect pitch but he was always close to the note I played as a game. But my suspicions were only confirmed in over this holiday when he told his friends mum her piano was a semitone out all the way. He thought her piano was amazing.... he told she must have had it especially tuned that way.
I made no issue with it, the biggest problem I find is that if his cello is out of tune even slightly on any string he will play till his ears and move his hand accordingly which is fine until you play an open string. This is how i suspected he may have perfect pitch when he start cello lessons.
However I like to say it doesnt help him with the aurals as he is not aware how it can help him or really understand what is being asked.
Now he is more aware I wonder if he will better in his grade 5 aural. He has past all his exams with distinction so far.
1. want to play fast, my son does that but I let him do it once and then tell him about all the little details and say play it again slower with this, this and this in it. Then build around that. He usually corrects himself and slows down as he is concentrating on what I have asked for.
2. I think frustration is the age they are at.... you asking a very young child for something very complex, they just dont have enough patience..... all my children struggle with that and overcome it 90% of the time even my 6 year old.
3. All children like to experiment my youngest favourite 5 mins is to invent his own tune to finish off his practice. He invented this part of practice

and the others are slowly following suit.
4. Um.... I think that is probably quite hard for them especially if they are reading 2 clefs. Has she realised that the treble clef in violin is the same as in piano. Believe me some of my students dont suss that one out for ages....... even the teens
5. Yes wanting to give up my eldest is good at that one on both instruments he frequently feels that way but wouldnt give up cos of the bands/orchestras and courses he can go on..... Meanwhile I while threaten to pack it all in if he fails to practice or continues with the paddies. He is nearly 10 and still has them so I tend to ignore or pack his instrument away before it breaks.
6. oh yes this doesnt seem to affect them so much now they are on the higher grades and there sightreading is good so that helps them.
I dont think your above list will necessary say that your child has perfect pitch because all my kids fall into all the catergories but only one of mine has perfect pitch the other two have not even got relative pitch. However I could be lying cos they may have but not developed it yet, as 2 years ago I would have said that no.2 didnt have perfect pitch.
I think you need to continue support her and I am sure it will all come together it is early days yet as 2 instruments is alot at their age.
My 8 year old does percussion as well and there are so many instruments to play but he enjoys all of it. He cant wait to start drum kit this term in band. He really has a passion for music. He is also academically 2 years ahead, a little like your daughters reading, he read at 2 years. It was hard going.
let me know how she gets on