Pressured by MIL to have another child

So the title is pretty much self explanatory. Today my MIL asked if my husband and I planned on having more children (this isn’t the first time she’s asked or the first time we told her no). My husband wasn’t around to help me out and I told her no we weren’t planning on it. To which she replied “but Taliah (my daughter) needs a sibling! At least one.” My husband and I have talked about having more children a lot and both have decided we are one and done, and we are perfectly happy with our decision. I guess what I’m really wondering is if anyone has also gone through this and what advice they might have to answer questions like this.