Toddler discovering their genitals

Help! My 2.5 year old has been "massaging" herself for the last few months and my husband and I have no clue what to do. She first discovered it a few months ago we noticed she would use her car seat straps. We thought she had a rash she was trying to itch or her diaper was full and it needed to be changed. We thought this for a while until she started doing it elsewhere. Then we figured out what it was. It was getting out of hand so we said you can only do it in the car seat. Now she does it all the time in the car seat and we don't know what to do. I know it's normal around this age but need some advice because I think it's getting excessive. We've talked to some friends about it but they completely shame their kids. Saying things like "ew gross", "no it's dirty" etc. I don't want to shame my kid but at the same time now I'm thinking maybe I should have? So confused.