As other have said here - it sounds like you and your mom appreciate Hermes craftsmanship more than her 'friend' that only buys Birkins for the show factor. When you truly love a brand, you buy more than the popular bags. Sounds like your friend is purchasing a Birkin to dress and impress more than the love of the brand. Boring.
Personally I don't own a B or K, I do own a Picotin and Jige that I love. I would like to own a Kelly and will likely get one in the future when I do want to dress up and definitely not for practicality. But for everyday, I'm a bit embarrassed to wear a bag everyday that is so recognizable where everyone who recognizes it knows the cost of it. There is something more modern and refreshing about carrying H (or any brand for that matter) that aren't the most popular bags.
The same goes for Chanel. Never wear my flap bags, but love my executive tote.
Totally agree