One of the most challenging skills for new readers is learning vowel sounds. I have included below a website that has some great vowel sounds posters that you can print for free. I have these same posters in my classroom and I find that the students refer to them often when reading and writing. You may want to consider printing out a copy for home to help as you practice reading with your child.
The website is www.readingmanipulatives.com. Please follow the steps attached to get to the free posters.
Directions to find short vowel posters:
Under Free Teacher Resources, click on Student Instructional Aids
Under Short Vowel Posters and Songs, scroll down and click on View/Download Resources.
Under Short Vowel Posters, click on Download Short Vowel Posters.