Their parents were/are nice people. They each worked. They shared custody after divorce. They re-married. The kids didn't play any sports, weren't a part of any clubs, didn't really have many friends, and she doesn't remember anything unique or fun about her childhood, just as she doesn't remember anything terrible or abusive either. Non-descript. They just lived their lives day-by-day, and now she continues to exist. She has one friend that she's semi-close to, and can't figure out why she has such a hard time making good, close friends.
By all accounts she was loved, cared for, given food and opportunity when she was young.
But the problem here was that this family just went along with the tide of life. If the kids didn't initiate doing something, then nothing happened (and have you met very many kids who pursue extra-curriculars all on their own?).
My friend never learned to "get along" with someone with whom she had a dispute. If she didn't want to play with her sibling, she just didn't do it. If she didn't like someone, she didn't have to learn how to work it out or talk through it. She wasn't challenged to try new things - try a new club, try a new sport, take a chance and see what it's like to be surprised.
Parenting on Purpose means doing the hard work of looking forward into the future, deciding what character traits and goals you hope for your child, and then putting your best foot forward to implement the necessary steps today.
You want your child to have healthy relationships in the future - teach them to talk to you and negotiate with you. Encourage them and create opportunities to do things they don't want to do (but they are safe) because their friend wants to try it - teach them to think through: is this safe, will someone get hurt, what happens if I like it, what happens if it turns out wrong, what is the value of my friendship with this person?
You want your child to go for their dream jobs someday - they need confidence! Encourage your child to try out for teams now. Let them feel what it's like to be rejected from the team, but it didn't "kill" them to be rejected. Let them feel what it's like to be accepted to the team. If they don't try for anything they won't know how to react in the future when putting themselves on the line is worth a job, promotion, spouse, etc. This teaches them to be vulnerable to say what they want and go for it. Teach them that.
Parent your child on purpose, don't just go with the breeze or the tide. You'll be so happy you did (and so will your child when they're all grown up) - even if they're grumbling about it today (no child wants to take emotional risks, they'll resist, but you are their cornerstone, their grounder, their safety net - now is the time while they have you. You know this, they don't, let their grumbling be heard but don't take it too much to heart.