A good spelling program will teach students spelling patterns not vocabulary words. Often spelling curriculum is left up to the school and sometimes decided upon by the teacher.
Education.com has some great articles and resources that you should check out on spelling. Just put spelling in the search box and you will be a long list of links.
If you want to help your child with spelling (especially now that summer is just around the corner), I recommend the book Words Their Way by Donal Bear. This would be a resource for you, not a workbook. It is a book that teaches kids how to look for patterns, sort words, make connections and really become a good speller. It would something that you could use all the way through 8th grade. So it would be a good investment.
It seems as though your child is ready to learn how to spell by syllables. This is what The Wilson Reading System and Wilson Fundations uses. It is a fantastic way to teach children how to spell words. Does your child's district use Fundations? Spelling by syllables and learning word rules, allows your child to break words into smaller parts. For example these words have "le" at the end. They are also learning the difference between the hard and soft sound of the letter c. You could ask his or her teacher to help you understand the rules that go along with the words.
It's much more normal now than it was before to have such difficult words in 1st grade. Whether it's good or not or whether such difficult words actually help children to learn how to spell is another matter altogether.
I think spelling words in first grade should be given in word families - sake, cake, rake, bake, fake - and just, rust, crust, dust etc. That teaches the underlying phonics.
But these days some teachers assign fairly random words as spelling words. Education is less concerned these days with whether what they're doing is developmentally appropriate - education now is mostly concerned about whether it's 'hard' enough or 'rigorous' enough.