I was also a chronic pot smoker for many years. I used t tell people the same BS.
That it helped my anxiety
That I couldn't eat without smoking
That I couldn't sleep without smoking
and the list goes on and on. If she went to a therapist they'd want her to sober up and then if the anxiety continued they'd prescribe something. When coming off pot after years and years of smoking I was a raging b*tch for days and days. Now that i've been off it for a while I'm glad I escaped from that stoned hell I was trapped in. Pot withdrawal sucks for short term but is so worth it long term.
Good Luck