Nitrogen deficiency poorly plant EASY FIX???

Hi chaps,

so after my old thread i come to my conclusion of nitro def after all the help and advice on here, i can really see now that the plants growth is very very slow if any atall is there a quick emergency fix for this?? i am giving them big bloom nutes and noticed it contains no nitro?? i do have some veg nutes witch or course contains nitro! could i give her a quick nitro boost with the veg nutes i have??.....Am i going to LOOSE one of my girls???!!! or will she pull on through. HELP PLEASE

cheers