For a second grader that teacher is pretty tough on her. Some second graders are slower in writing because they're perfectionist writers. This is a good trait. To not allow recess is doing the opposite because she now thinks she's being punished for not writing good making her slower with perfection in mind. If this teacher can't reason with logic then maybe the principle should intervene. Recess is a development not just fun and games, although for a kid it is fun.
My daughter has also had speech problems and is very shy. She's a twin, and she has always mainly played with her twin sister. Last year, she finally started really making friends. I really think that recess is important for her social and speech development.
I can make it all legal, and I think I will. She's has an IEP (Individualized Education Plan), and I think that I will add a goal that states that she will not be taken out of recess.