It doesn’t matter that your daughter is using Spelling Wisdom 1. The grade levels for each book are only suggestions. What is important is that you choose the book that is appropriate for your daughter’s ability. If she is finding that the words in Spelling Wisdom 1 are too easy, either skip ahead to an exercise that has a few words she’s not sure she could spell correctly, or move her to another level of Spelling Wisdom.
Keep in mind that each Spelling Wisdom book is two years worth of dictation exercises if you use them as recommended. Each Spelling Wisdom book starts with shorter dictation selections and ends with longer ones. It is not the length of the exercises that determines the difficulty of the level, but the words in the exercises.