I think it’s a fantastic question something you could apply to all love interests in comics. Easy answer is that she’s not the main character so therefore not explored in that level of detail. That said others have commented that Supermans friends are other heroes and aliens which brings me to my point, they’ve downsized supporting casts that no character really has anyone who would be their friend. The only characters that are allowed anymore are other supes. And it like that across character and companies.
One could argue that this is one of the reasons why the character and secret identity of Clark is so important. He can be a regular guy with regular friends.
(Full disclosure, I actually do like the context of how he revealed his SI and don't necessarily mind it as the current status quo. But I do see the other point of view as well.)
“Look, you can’t put the Superman #77s with the #200s. They haven’t even discovered Red Kryptonite yet. And you can’t put the #98s with the #300s, Lori Lemaris hasn’t even been introduced.” — Sam
“Where the hell are you from? Krypton?” — Edgar Frog