@Jennifer Moore and @Jorge De Jesus You both have asked great questions that are best answered by your state's Real Estate Commission or at the very least an experienced RE attorney in your area. 

Amber and her husband are very experienced in finding deals and analyzing. 

It's my recommendation that you seek the advice of an experienced attorney.

I am not experienced in new construction however I have done couple of semi-successful filliping already.

The other thing to keep in mind is that crowdfunding sites haven't been around that long and have not experienced a downturn.

I would like to see what other and more experienced investor recommend.

Plus permits and engineering   It will cost you quite a bit .  

I am curious what some of you experienced investors would think about this park. 

So you can work with your sister, or try to groom someone into being a competent/excellent manager, but finding an experienced manager will be challenging- until you've expanded your footprint substantially.

I say this as an experienced student rental property owner and property manager specializing in student rentals.