I hate to laugh, but it "is" funny...these lil girls can't seem to zip it up! My daughter is on the sticker program...one each day she shuts her yap, and does all her school work on time. At the end of the week, if she has a sticker for each day there was school...she gets to pick something special...one on one with either hub or myself. So far, she's picked a trip to the local thrift store with me...without anyone else every single week. lol
I can only assume your sd lives with a nutjob, and only sees her father EOW. (because of the SASE's you're sending to the school). Without proper "praise" at her moms house, why "would" she fix this problem.
So, whenever she's with her dad, he should make it a POINT to give her extra praise for the stickers she DID manage to get...(and that's if she gets a sticker like my daughter does). If, for example, she gets to dads house and has 10 stickers for the previous 2 weeks...do something AWESOME. Something that will blow her mind. If she only has, say, 5 stickers...let her know how proud you are that she tried really really hard, and you're VERY proud of her for getting those 5 stickers...and then do something "smaller", like a trip to the park or a simple walk.
Kids need encouragement and praise...sounds like moms sentence writing thing is working "really well", isn't it? Maybe if mom gave her some time and POSITIVE attention, things would get better?
Is it possible her dad can call her every day after school to find out if she got a sticker? She'll be on cloud 9 if dad does summersaults each day she gets one, and high fives her all over the place. If he acts all excited (and I mean overly excited...lol) then she'll figure this out on her own. "I do well in school, dad goes crazy with excitement...hmmmmm". See?
I don't know how dad should respond to the teachers email...but I'm thinking with a whole lotta whooping it up with fun and excitement and an awful lotta praise, this child will change her "odd" behavior at school in a short amount of time.
ps...this works SO well with lil miss, that if the Aide doesn't have "time" to get her the daily sticker...she gets ALL types of depressed...so the Aide tells her that when she comes back to get her brother after school (she only goes 1/2 day) she'll make sure to have the sticker waiting. My daughter loves it THAT much.