My mom can borrow anything she wants at any time. She could rip my stuff to shreds and I would still let her borrow.
I would let (and have let) my two closest friends and one of my coworkers borrow any bag they like. They are all really into high-quality goods and take better care of their stuff than I do.
I have one aunt and a cousin who I would let borrow *certain* of my bags if they asked.
As for anyone else, probably not. I don't like lending my stuff out to people.
As for borrowing, I would only borrow from my mom. I would worry about the borrowed bag (getting it dirty, scratched) too much to enjoy carrying it.