Making the decision for yourself is definitely the best way to go. Joining a soror is for life, so it's important that you like the one you choose. Point out to your friend... if you join the one I like,but don't really like any of the girls except for me... what are you going to do when I'm not around at the events because I'm sick or have class or whatever. Also point out that it won't be as fullfilling an experience if she joins just because it's where you want to go, she'll resent being in and be one of those girls who just wears letters and doesn't really want tp be a part of the org. Also point out, if she's afraid about the whole making of new friends... wherever she gets a bid from, they like her and want to make her a sister... and if you do end up being in different sorors its an even better opportunity for you each to meet new people and make even more friends, you can each introduce each other to your sisters and expand your social circle