Nothing particularly inspirational to add, but thought I'd throw in my own experience.
My parents have always been extremely supportive of what I do, but they are also very risk-averse, and always have been. Not understanding real estate, and the comparatively large sums of money involved, make my mom, especially, worry pretty strongly about what I'm doing. I find you just have to be able to push through the constant concerns and the well-meaning advice, and take the risk. Even if it's not at all overtly hostile, the subtle negative drag does tend to sap your enthusiasm at times. Just gotta remember the end goal and keep pushing through.
I see it mostly as fear of the unknown, really. First it was worry about keeping our old house as a rental when we moved into a new one. When that went well, and I decided to try to buy a duplex, it was worry about managing multiple tenants, and fixing it up, and ongoing repairs. I think there will always be items you have to deal with, and you just gotta accept that as the cost of doing business in order to build wealth for yourself. That's easier to do when you're the person who's making it happen then for those outside who don't quite understand why you're willing to take a risk.
My family, though skeptics, were very helpful when I was fixing up the property to rent, especially my dad. He was there laying floor, helping me fix plumbing, and putting in new toilets. I think they're slowly coming around, but you still gotta keep pushing through the doubts. It would be awesome if they would get as excited as I am about the prospect of finding additional units, but I've accepted that's not terribly likely, and that's ok. I know they'll be there if I need to get a new water heater in, repair the trim, or figure out landscaping.