Well big surprise, another mother in law conflict. I realize these issues are so common but here goes my question, or perhaps I'm just looking to hear some options or advice on this situation. You can be blunt with me!

This happened a few months ago, and once and while it pops up in my mind and doesn't sit well with me. Oh and the irony of a "counselor" asking for advice! However many people in the field encouraged me and other students to ask as many questions as I could, and get as much therapy as I could for self improvement.

So my sister in law (10 years younger than me) had been looking at colleges and programs and stated that she wanted to be a counselor and help people. While my mother in law was over she made a statement something of the nature as "Can you believe it she wants to study counseling?" and referred to it as a bad job to my husband and I. I know she is well aware that's what I had studied, but I was still surprised she had said that. However my MIL is unaware that I have PTSD, which is my reasoning for not working directly in the field so far. I'd like to perhaps someday in the future if I do feel ready to, but for now I'm far too triggered by the situations that I might encounter working in that field. I believe my husband had mentioned to her years ago, early in our relationship that I had a difficult upbringing and that some trauma had occurred, but I doubt she had connected the two. I believe my MIL's sister had a role in influencing her perspective on psychology or counseling as well being that she had studied psychology/counseling in the 80's and received her masters, and tells everyone that the requirements had changed during that time and she couldn't be a psychologist with her degrees (even though I know she would qualify to be a therapist). The MIL's sister has a well off husband and choose to be a stay at home mom. I had also heard through my husband (told to him by his mom) that the MIL's sister has PTSD, through sexual trauma that the MIL and her sister both experienced as a child. My MIL had told my husband that despite recognizing it was a messed up event that she doesn't understand why her sister just can't "get over it" and move on with her life. As you can see this is one of the reasons why I've been apprehensive about sharing that I have PTSD, along with it being a very personal issue, also that she doesn't seem to keep things private at all amongst family members. Anyways I have been happily working in a related field throughout this time, which does use my degree. Although I still don't think that my MIL understands that my field is related, or that I'm using my degree.
So my sister in law has decided to study biology now, which my MIL thinks has far more prospects. Which I'm sure she will be good at, she's very bright. But I do feel bad that her true passion is being swayed, because I thought she would make an excellent counselor.
I'm just looking for some feedback on this situation, ideas on what to say or how to deal with it. Feel free to ask me anything else to help better understand the situation. Thank you.