I'm coming late to this thread because I thought it was a less serious situation than it seems it is.
My angle: One of my DDs was diagnosed with a mental illness. I discovered as a result of this that everybody in the whole world thinks they know how to treat mental illness, and that they all have an infallible 'quick fix'. I also learnt that it is one of those things that people want to Just Go Away and so they will get antsy and decide that the doctors are 'no good' if the patient has not made a full recovery in a few weeks/months. Fortunately for my DD, this was all filtered through me. As it was, standing guard/gatekeeper for her in this particular aspect of things meant that *I* was almost driven to distraction. Note that this was all from people who love me, and her, devotedly.
I am honestly feeling genuinely horrified to think that you might be going through even a half of the pressure that I was exposed to on her behalf, without having someone to advocate for you. Please, don't give your sister, or your mother, even a millimetre of ground. Don't say thank you or anything positive about the gift. This is all happening because they want your problem to 'go away' so that THEY can feel better. The doctors aren't fixing you fast enough for *them*.
In the end, I flat out said to the people that I needed support from "I know you think you are helping, but you are not. DD is in the care of experienced medical professionals. Mental illness is complicated and takes a long time to recover from/control. You need to either back the h-e-double l off or just don't discuss it with me anymore. This doesn't help." There was a slight extinction burst where I would occasionally have to repeat "This doesn't help. Stop now." before people either listened and started being PROPERLY supportive or simply went away.
For the love of all that is holy, PLEASE don't thank your sister for the book. She needs to grow up and get over her insecurities. This is about YOU, not her, and she can either deal with it or get out of Dodge. At the moment she is being really, really selfish and she doesn't deserve your consideration.
Please feel free to PM me anytime.