Multiple companies a conflict of interest?

[Bruce M.]

Hello all. Here is my prob. I want to start a company for buy and hold and possibly flipping properties, once the market gets better. The 2 people in charge of this company will be me and my sister....Let's call it Company A. I also want to do investments with my wife a few years down the road and we'll call that Company B. My sister does not
want to form Company A if Company B has a strong possibility of happening. What do you all think? Is she in the right?