too late to trim???

My situation:
I put a White Widow into 12/12 on the 5th of dec. (about 3 1/2 wks ago )
It is stretching a little more than I anticipated and I only have about 12 to 14 inches that I can raise my lights. I'm hopeing that the major stretch is over and I will not have any problems.
All the other plants in my grow where topped befor being flipped, for some reason this one plant was not, and she's getting tall.

My question:
Is it too late to trim some of the top off? or will that be causing more problems, as loss of yeild? Or will the plant make up for the trimming on its lower branches?

My setup:
Indoors, foxfarm o.f. soil, (4) 400 watt hps lamps

Thanks in advance

Just tie it down. LST. Problem solved.

I didn't know that a flowering plant can be 'modified' by tieing it down. I guess I assumed that all modification had to be done prier too putting them into flower. Thanks I will try that.