I don't believe so, but I'd like to clarify that gender doesn't (or at least shouldn't) have much to do with it. Does the modern man need a woman? Does he need another man? Does the modern, cosmopolitan woman need other women in her life? Do we need the planet Saturn?
I understand why the question was posed that way, due to how shackled women have been for much of recorded history, it was always assumed men and women would rely on one another and now that's not the case. I just mean to respond by saying that other people, regardless of gender or romance-ability, shouldn't be "necessities" in any way, shape or form.
They're nice to have around though. Someone else made this computer I'm using, this website, this question. Someone else made the chair I'm sitting in, the desk the computer is on and the house I'm currently under. But if I really set my mind to do all of these things, I could have. It would have just been really tedious and boring.
I'm assuming the question was meant to be in more of a romantic-type of way, but I can't really answer that. I've always seen romances as extended-friendships. If we're debating whether or not we "need" friendships...well...
“Friendship has no survival value; rather it is one of those things that give value to survival."
(I suppose my straight answer would be: no. She would survive just as well on her own. She would just enjoy life a little more if she brought more people into it, and allowed them to help her.)