Yeah, I definitely wouldn't recommend. Acid exposes someone's mental state all too powerfully. Finish her treatment first, then once she can live without medication and not get depressed then she might give it a go.
My girlfriend is in fifth year medical school. About a month ago, she had to interview this guy in his early twenties. He had a history of being depressed, and had gauged his eyes out after taking acid for the first time, causing him to think he saw the devil.
I love acid, and have the best time of my life. But you can never be sure, and need to be strong mentally. Also, she'll want to have a good handle and understanding of everything that causes her to be depressed, or acid might freak her out.