The phrase beginning the size of doesn't make sense at all. Perhaps the translator got mixed up during editing and meant the sentence to read I believe that Gohonzon was one that could always be kept close to her no matter what she was doing, especially for her children. I'm just guessing though, there's really no clue in the text of what was intended.
In the second sentence, of a small size could be replaced with small.
Student or Learner