You went with the Strawberry Kush? Definitely odd that she's not flowering. I had this happen once before that I can recall off hand with some of the Where's My Dog and when I went digging for information it seems that odd ball Semi Auto/ FV pheno's can just pop up even well into the breeding project which could possibly be what you have going on here with this one. If that is the case and it is a semi auto pheno I could suggest a few possibly ways to get it to flower. Feed it banana , peach, and or apple ferment this will increase Ethylene production and could trigger the flowering to occur, sometimes giving the plant a 24 hour dark period could trigger the flowering, I know the semi auto's are very light sensitive and sometimes just reducing the hours of lighting by an hour or 2 can trigger flowering to occur.
It could also be a rooting issue or some sort of unseen stress causing it to not flower however it looks to be a healthy plant. What is your light schedule on them? Have you noticed any pistols on it yet?