You should also be working on site words with your child each night. It should not be over 3 to 5 minutes of you showing them the flashcards. Remember the rule 7/10. For every seven they know, add in three that they don't. This will give them the confidence to keep trying. Quickly run through the cards and pay attention to which ones they are consistently getting. Just because you were finished with a list doesn't mean you should put those words away. Keep those out for your bank of words that they know and always review them so that they are not forgotten.
My main goal for your child is for them to love learning. I want them to come home and tell you about their day, not dread doing homework! They should be active and playing and be kids!