So, while having a thought, I browse in the internet to get some artistic design that I could use to produce it. I took a picture of balloons, birthday cake, an angel, a gift, a tag, a stripe background and a picture of the celebrant.
I've made two different designs:
design #2 (blue green and yellow party with picture of the two celebrant)
This morning, I presented it to my client. Unexpectedly she likes it both. My design gave her a great impression and excitement. So I feel great too! =D