I never had the impression. I have two middle names and I could have kept them secret from just about everyone, had I wanted to. They didn't appear on my class list, on my certificates when I graduated. Never put them on my resumé. They only show up on my passport. I think they're not even on my health insurance card. For years I didn't know that one of my best friends was actually named Mary. She goes by her middle name and just never told anyone.
Of course you have to show people you work for your passport or something similar for identification but by then they would already have hired you.
I just think you can go crazy with middle names because hardly anyone will know about them. I'm more worried about whether she will like it. But I guess you can never know whether your children will like their name anyway.