My five year old daughter asked me if she could print out a heart she drew one day. She happened to be very specific, so I asked her to design it with me. She had a pink ruler slap bracelet on, and was able to tell me the sizes of everything she wanted so I said ok. At that point I was in the middle of printing out parts for my students on my personal printer (school Makerbot was down) and was swamped with work, but what designer can say no to that.
We made this heart very simply with a mirrored half circle and an arc, then extruded and filleted it in AutoCAD. It was her first 3D CAD design and she did a great job. She has continued to ask to design with me and I hope she keeps the ideas coming. She simply adores these hearts and keeps them in her homemade treasure box so I hope you will adore them too!