Wife is not comfortable REI

[Tyler Hardy]

I'm a new investor and I'm on the hunt for my first deal. I've been narrowing down my search and I'd like to start in smaller, commercial multi family (5+ units). The issue I have is the up front capitol. We recently built a house and put the large majority of our liquid capitol in it to keep our mortgage down. This way, when I finally get to the point of leaving my day job we won't have a huge monthly payment to cover, and we're not paying as much in interest. Unfortunately this leaves with with very little to invest. 

My issue is this, I'm thinking about using a HELOC to start investing but I will only do this if my wife is comfortable with it (being that this is our primary residence). I chose a HELOC because of the lower risk of default, and the fact that it won't change our mortgage payment like a REFI would. Because her parents were both agents before the crash and basically lost everything, she's hesitant about investing. How can I have the conversation with her that will put her mind at ease? Should I even try to push the issue if she's not comfortable? I'd like to have access to the 200k or so of equity I have in my home, but it's not worth her laying awake at night stressed about the risk. Thoughts?