Topping at this late end of the season is just going to stunt this plant.........it will take 2 weeks to recover, by which time flowering will be almost commencing, meaning you will lose 2 weeks of further growth for no real benefit.
Continue with a bit more trainig, otherwise just leave her be without any stress (topping) and let her finish naturally.............this will give you maximum yield at this point.
Topping a month ago would have been a better idea, but topping this close to flowering is not ideal.