I thought this fusion was kind of obvious. Spinel, the fusion between Pinkamena Diane Pie and Amethyst Quartz. Yes, this goes along with Rainbow Lapis and Star Iolite. Also, making the barbie-doll proportions and trying to make them thicker was quite the challenge, so I hope this works!
 
I imagine this fusion would be very fun loving and excitable, but at the drop of a hat could go in for a nap or stay in bed all day eating chips and watching TV. She literally gives no shits although really, she does actually give a shit. She wants to be that fun loving girl everyone knows and loves but she’s not really all that fun all the time…