That said there are a lot of different definitions of friend. People you like to hang out with is a common one. I prefer to use one as a measure of the degree of mutual selflessness one would engage in, and mutual trust. There are people I haven't seen in a decade that I'm perfectly content not to spend time with because our interests have diverged. But they have good hearts. I'd trust them to be in my home when I wasn't there, or watch my children (I don't have any children, but if I did), and if they really needed me I'd be on a train out to help them at the drop of a hat.
Of course, absent specifics it's hard to know what your mother had in mind. Rather than either of those definitions she might have been instructing you to have compassion for someone who is vulnerable and in need of an ally; to show kindness to someone who could use it. There is nothing wrong with a preference for the company of people with certain personality traits. We all have our own interests and types of people we "click" with. That said, never fall into the trap of thinking morally neutral traits make you better than someone else. When you take it upon yourself to set standards for other people, life has a way of humbling you with them. You're young, though, so I don't expect you to take that lesson to heart until you learn it the hard way as virtually everyone who has come before you, myself included, insists on doing.
