My mom is criticizing how I allow my daughter to use social media

I have a 14 year old daughter. Like nearly every teen, she likes going on the internet. She likes social media. She is a very creative girl. She loves art and design. She has an Instagram and a Pinterest. I have the rule that she has to tell me when making accounts and I have to be friends with her or whatever. My mom is also following her on these accounts.

Currently, the issue my mom has is her Pinterest account because my daughter has made a Pinterest board for wedding decor. She pins different wedding dresses, venues, and things of that nature. My mom has a problem with that and says it isn’t “age appropriate.” I don’t agree with her. I think dreaming about a wedding and how it’s going to look is very normal for a teen girl. My mom thinks this means she is wanting to get married early and “advertising her availability.” I’m really bothered by this. I don’t appreciate her saying these things about my 14 year old! I mean this is normal behavior for a teen girl, right? I feel like she’s making it something wrong when it’s innocent.