The context of a word is crucial for understanding its meaning and use. Thus, to fully grasp the meaning of a word and to be able to use it proficiently, children need to become familiar with the word pairs of that word, that is, words that are likely to appear together with the main word.
Why word pairs and familiar context is useful for out 'lazy' brains
One of the reasons that learning word pairs is useful is that our brains are 'lazy' and when two or more words appear together enough times, we stop analyzing them independently. They become a single unit in our head. In fact, experimental evidence confirms that this makes processing and interpreting words much faster. 
For these reasons, as children’s vocabularies grow, explicit instruction of word pairs is crucial for them to make the most of every new word they learn. Importantly, this is even more crucial in the case of children with dyslexia in that these children have been found to compensate for their limitations in reading by relying even more on the context in which words appear than children without dyslexia.
Thus, helping these children familiarize themselves with word combinations that are used in statistically predictable patterns is absolutely essential.
At Mrs Wordsmith, we have our own group of machine learning experts that gather the most relevant texts and integrate them to make a gigantic database consisting of a variety of sources. Our writers then use this database to check which other words are most commonly used with it and they list them as the main word's word pairs. Given our goal to help children become better and faster readers, we've made word pairs an important aspect of our products and this feature makes them particularly beneficial for children with dyslexia.
Sources for further reading:
 Conklin, K., & Schmitt, N. (2012). The Processing of Formulaic Language. Annual Review of Applied Linguistics, 32, 45-61.
 Nation, K., Snowling, M.J. (1998). Individual Differences in Contextual Facilitation: Evidence From Dyslexia and Poor Reading Comprehension. Child Development, 69(4), 996-1011.