Is she starting to flower? Next step?

It's hard to tell from the photos but since it's an auto and you're 7 weeks in, if they HAVEN'T started to flower, there's something wrong! My autos all go into pre-flower by week 3 or 4 and flower by week 4 or 5... But don't worry too much about that as yours could just simply be different! I use Fox Farm nutes as well and I like to start them on Big Bloom just before they go into flower so now would be a good time. Cut back a bit on your Grow Big as nitrogen needs to be cut back when in flower. I would cut Grow Big in half and add 2tsp Big Bloom per gallon this week... next week, I'd again use the same amount of Grow Big but up the Big Bloom to 4tsp per gallon... when they're really going strong in flower, cut out the Grow Big altogether, use 6 tsps Big Bloom per gallon and add 1-2 tsp of Tiger Bloom per gallon. Plants look really, really good - kudos! And happy growing!