Girls Mini chopper

So I have a 30ish cc Robin weedeater motor I will be mounting on my daughters mini schwinn OCC, any hints or tips always good. Will be running bike chain, so I need to get home and do some measurements for the sprocket sizes. I will also take off the standard exhaust and do a mini straight pipe to run similar to the one on my ol chopper. Also will be doing custum paint, thinking Pink and Black, has to be girly as two girls will grow up with it. I am thinking of a cute lil skull and crossbones with a Bow as the focal point of the paint job.

Pics will be posted for sure, I just bought paint and stuff, I am hoping to get it done this weekend while she is away so when she comes home sunday she'll have a sweet surprise!
What size wheels on the Galaxy? I have always wanted to try a friction drive right behind the seat post, don't know how much modification that would require but I think it would look a lot nicer and be more incognito that way.