Was I wrong ? Quick question ...

So the day when I was discharged from the hospital after having my baby it was July 4th. My mom was cooking out so I decided to go with my son and boyfriend. As soon as I get there my sister goes to pick up my son but before she picked him up she asks me for the blanket and I tell her that it's in the diaper bag that my son's dad was carrying. And then I go to ask her did she wash her hands before picking him up because I just wanted to make sure. Prior to us coming there, I'm sure she was helping my mom cook and things like that, so I wanted to make sure. Point blank. Then she goes and says " Yeah, why wouldn't I wash my hands before I pick up a baby? You acting weird as shit" So I say " Well, I'm just making sure because when I came in you we're already sitting here and I don't know if you did or didn't already." Then she says "Yeah I washed my hands ( shows me the paper towel ) like you asking me dumb ass questions acting weird as shit !" So I said "Well just don't touch him then" and I took my baby. I felt like she was being disrespectful to me by cursing and getting upset because I wanted to make sure her hands were clean before picking up my 2day old child. Was I wrong for asking ? Where did this conversation go left at ? Ever since that happened she hasn't spoken to me or acknowledged my child. **Not to mention as soon as we walked in the house she was taking about my son saying he was bald headed and saying things like "look at his head. Who head he got ?" to a cousin of ours. I never heard her say that but my boyfriend did and he felt some type of way.