think my plants have started flowering at 5" of height

got some ak47 clones from a friends at about 2" height, and i have messed up the light cycle alot because i was too lazy to buy a timer, so they've gone into flower.

if i just carried on flowering at 12/12, how much could i expect to yield per plant if they are so short?

No way to tell for sure, you'll just have to wait it out. Learn from your mistakes and you'll do better next time.

A photo would help, the rest depends on your setup, light's, medium, nutes etc.
but it's not unheard of to get an ounce.

Oops, just saw your setup which looks good apart from the vent is too small and is that tinfoil??
If so get rid of it and use flat white paint, it has higher reflectivity and a more even light distribution.

flower from 5" ouch very very little yeild if any
how long have they been on 12/12 because u might be lucky to force them back into veg
if its only been a week or so i would shuv them back into veg on 24h light
good luck

post some pictures