How to POLITELY tell people to “back off”

I have a 16mo old DD who for the most part is extremely shy around people she doesn’t know (and some people she does “know” i.e. my MIL)My question is, I know I need to stick up for my daughter because she cannot stick up for herself, but how can I do it politely? For example, DD was trying to follow her dad to a trash can at a restaurant and a strange woman blocked her path, came up to her and said “hi! What’s your name?” And reached her hands out to pick her up. What I wanted to do was say “don’t touch her!” But instead stayed silent and waited for my daughter to inevitably turn around and run to me to be picked up.And another example a little closer to home. MIL makes DD extremely uncomfortable. MIL thinks that she needs to force a relationship and that’s the only way DD will grow comfortable around her. My husband has had talks with her saying if she’d just back off and allow DD to warm up in her own time, she’ll come around, but MIL can’t help herself. Because DH won’t do it in the moment, how can I politely shut down my MIL’s invasive behaviors too?ETA: I don’t want to say “she’s shy” and it become a self-fulfilling prophecy. via /r/Parenting https://ift.tt/2NFCMxF