[Arbeely] had many acquaintances, but few close friends. (2.81)
The supernatural characters aren't the only ones who have trouble making friends—Arbeely seems to be more focused on his business than he is on friendship.
Slowly, over days and weeks, the Golem and Rabbi Meyer learned how to live with each other. (4.1)
Even though the Rabbi takes the Golem in, and even though the Golem was basically made to please a man, they grow together as friends, not as lovers.
"Please call me Maryam," she said, and there was a friendly smile in her voice. "Everyone does." (5.106)
Maryam isn't the type of person who seems to just be doling out acts of kindness for kudos, but instead she seems to be a true friend to people in need, in this case Saleh.
[The Jinni] wanted to resent [the Golem], but all he felt was an irritated bemusement. (11.149)
This doesn't seem like the beginning of a beautiful friendship, but it is. Even though they're almost polar opposites in many ways, the Jinni sees that he has a lot in common with the Golem, and he decides to explore this instead of focusing on the differences.
Was it strange that they weren't talking? The people she saw walking at night usually talked to each other. But […] the silence was not uncomfortable. (14.35)
It seems that the Jinni and the Golem have found something few friends do: the ability to be comfortable in silence.
"Why can't we just be friendly? Why do there have to be complications?"
"It's the way of the world," Anna said, shrugging. (15.14-15.15)
Anna doesn't understand how Chava and Michael can just be friends, since they live in a time when men and women only talk to each other when they're dating.
"You wore a hat," the Golem said. "Thank you." (16.1)
The Jinni wears a hat, even though he feels it compromises his identity, because the Golem asks her to. Yet he doesn't resent her, because he knows she means it as a friend, not as a means to control him.
At length they noticed her shirtwaist, and gasped and cooed over it, and begged her to tell them where she'd gotten it. The attention unnerved her, but it was so honestly friendly that she began to relax, even to smile. (18.68)
It didn't seem like Anna and the Golem will be good friends early in the book, but once the Golem wows Anna's friends with her impeccable taste in fashion, she's part of their social circle immediately. They just have to find something in common besides a place of employment.
Where, thought the Golem, did she herself fit in? Somewhere between mother and daughter, she supposed: no longer innocent, not yet understanding. (22.28)
In "between mother and daughter" means that the Golem is perfect for the role of friend (like Jennifer Aniston. Lisa Kudrow, or Courtney Cox) to all the new girls at the bakery. She serves as both friend and mentor to Ruby, who is immediately stressed about the job.
She'd never even been his lover! And yet the memories refused to lie still, to grow weathered and distant, the way he desperately wanted to. (23.103)
The Jinni doesn't seem to understand that it's possible to like the Golem, a woman, in a non-sexual way. What? Be friends with a dame? Unheard of.