All you can do is give her everything she needs and hope the genetics are good.
Stigma on day 12 is quite surprising though! You probably have another 5-7 days before she starts to stretch and she will likely triple in size. Normally it's double, but given how early this one decided to flower, I think it'll triple. So if it's 8" now, get ready for a 2 foot plant in about 3.5 weeks.