No one can tell you that for sure.
It is a sativa and it look like its only been flowering for about 2-3 weeks max and probably not at a full cycle of darkness because it was outdoors.
Now its indoors i reckon you can expect a good 10 weeks longer from it on 12/12 light cycle and it may grow another 12" in height or more by the time its done.
Feed it molasses weekly at a rate of 1-2 dessert spoons per 3 litres of water to fatten it up.
Always have more than one plant saves on plant paranoia lol