Clarifying question: does she have a diagnosis of ADHD, or just vague "attentional weaknesses"?
As to ADHD and reading: many children with ADHD are slow to learn to read, most likely because of the executive function/working memory/automaticity side. Once they learn to decode, the usual long-term difficulty is with comprehension, and then later with inferential comprehension in particular. The corollary is difficulty with spelling (working memory/automaticity, as well as poor self-monitoring), and then later with (lengthy) written expression (especially initiation, organization, and using writing for literary analysis).
At age 7, you are a ways away from the higher-level deficits that usually crop up (and often are not identified at first glance, because of the length of reading selections and writing samples used in many standardized assessments). Not that these are not an issue now, but that expectations are so low for reading comprehension in 2nd graders that it will be a challenge to document even her personal weaknesses, let alone normative weaknesses.
For documentation of dyslexic-type decoding deficits, I would suggest an assessment for phonological processing (CTOPP-2, PAL-II, some supplementary subtests of WISC-V and WJ-IV (latest editions only)), with an emphasis on the later-developing PA skills, that involve phoneme manipulation, rather than the early, surface PA skills. Often one sees discrepancies between real word naming (letter-word ID, word reading) and nonsense word decoding (word attack, pseudoword reading) in children who have learned a bunch of words by sight, sufficient to look average, yet don't really have solid underlying decoding skills for novel vocabulary.
Even if the district qualifies her as dyslexic/SLD in reading (which is what IEPs typically call dyslexia), it is highly unusual for a school to pay for outside decoding/encoding intervention. Most school systems have an inside person with similar training, though rarely Lindamood. More typically, you will see other systematic multi-sensory instruction in decoding/encoding skills, such as Orton-Gillingham or Wilson. Both are effective, btw. If they have OG or Wilson and you strongly prefer LB, plan to pay for LB privately.
