How to get her off the morphine and onto the Herb?

Hey all, just had a few quick questions for you. So my mom has recently been diagnosed with Arthritis, and she's been going through a lot of pain. Her doctor prescribed her with morphine, but, knowing basic knowledge about morphine, i know it can be very addictive and dangerous, so i thought a better approach would be to introduce her to the herb, agreed? She also has sleeping issues, sometimes she only gets 3-4 hours of sleep and is extremely tired the next day, and i feel really bad. There are a few issues here though:
1. She doesn't know that i use marijuana, so doing this I would have to confess in some way.
2. She thinks marijuana is a horrible drug, like meth and all that, what would be the best route for me to take to convince her that it is a much better option than morphine.
3. I live in Indiana, which means 2 things. The first would be that marijuana is illegal in the medical form in Indiana. The second, would be that she had to buy through a dealer (I'd do it of course) and i don't know if she really wants me doing that, knowing that i could get into a whole lot of trouble, and lose a whole lot of money. I don't think she wants me to get caught, since it can ruin my chances of going into med school in a few years. So my question here is, how should i get her past the fact that it's illegal and that you can get caught? I'm trying to do this all for the better of course, and this damn legal issues keep getting into the way :/.
Thanks for reading all of this, sorry for it being so long :/
How do you all think i should approach this situation? I know there's but i have no idea where to begin.... This is why i come to the City for help! Gimme a few of your opinions