OMG. Negative mother in law...how do I handle this!!?

[♥.mσmmч²]

I am trying to overcome my very negative mother in law. She can hardly just be happy for the things that others have. My husband & I live in a very small two bedroom apt & found out today we are going to be moving to a 3BR 2Bath home in a nice neighborhood for my little girls to play in. My little girls have NO place to play now, no yard, nothing. So my husband told my MIL we were moving & all she had to say was "well...how are you going to mow you yard" (cause we don't have a mower!). It just got under my skin. She didn't steal my thunder, but geez. Last time she came to our apt, all she did was critique it. I feel like if she does it this time at our new home, I will just let loose on her...How do I deal with this negative mother in law!? Thanks in Advance.