If its 3 months old, you can flower any time. But here is what I would do.(transplant into a 3 gallon) I would take off the bottom branches with a clean razor nice and neat like just the bottoms, clone them or toss them. Then wait 2 weeks for that area to heal, in the mean time the other branches will be growing up and the nodes (bud sites) will be filling in.
There not going to get much light down there so what you will be doing is redirecting the hormones into the upper branches and fatting the buds.