Peeved at my mother-in-law

My MIL doesn't know I'm pregnant yet. But the topic of adoption came up in conversation. Before I left my job I was a Nurse employed by my states office of mental health doing home check-in's on children of special needs (usually being fostered) 
I always said I wanted to adopt regardless of having my own children or not. I just feel like there are so many children that grow up in the system and need loving parents. My husband and I always talked about adoption or even fostering both having backgrounds in the special needs community. My MIL flat out said to me "why would you ever adopt a special needs child and complicate your life? Or any child for that matter when you can have your own?" and then proceeded to go on about how expensive it would be and I need to have my own child. Then asked my husband and I if we were trying to get pregnant currently. (Intrusive!) She's rude all the time, I can't even get into that. I have soooo many stories it's a joke! But it just ticked me off! It's my life and my family. Like those children don't deserve love!? I didn't say a word because I would probably say something I regret! She's just so intrusive! I wish she would go away.