3 Bdays In One Day

This past weekend was two of my older sisters kids and her sister in laws birthday party. My sister had requested I do three separate cakes, but I decided to put the three cakes together making it a three tier cake. She had first told me to make a Wonder Woman cake for her daughter, a construction cake for her son and a guitar cake for her sister in-law. When she told me this I was like, "Oh my!". I would've done it, and I don't want to sound needy and stuff but I didn't have the money to pay for it all and she wasn't going to pay me cause it was a gift from me to them. After a while, she then told me to put her son and daughters cake together into a full sheet cake but still make a guitar cake. So that was a bit better. Then I couldn't find any