I agree with aculady, I'd ask the school to evaluate her for learning disabilities. What you described with the cards and not being able to come up with ideas could be just a 6 year old with a great concept who ran out of ideas and needed a bit of a prompt from someone else... or it could be a child with disorder of written expression - it sounds a lot like my 2e ds. Also kids with dysgraphia can know the alphabet in order at 6 - my ds definitely knew the order of the alphabet. He reversed some letters then, but his teachers said it was developmentally appropriate and that letter reversals continued for some kids until they were almost in 3rd grade. That said... he is dysgraphic... it's just not easy for a parent or teacher to recognize in a young child. It's the same with other challenges too - with our 7 year old 2e dd, we thought she had a reading challenge and instead found out she had a challenge with associative memory - we (parents and teachers) would never have figured that out without the help of an assessment by a professional familiar with LD.
I wouldn't worry about the school psych laughing if you share your concern about a possible LD. I also wouldn't be surprised if she doesn't think it's a concern... and if that happens, what you need to do (and should do anyway) is to document your concerns and request for an evaluation in writing.
Good luck! And fwiw, I think you type very well with your thumbs
Loved your dd's 100s day idea too!
polarbear