What is「に」 functioning as?

[Daniel]

Hello, everyone.
I'm fairly new at Japanese, and I've come across a sentence with a grammatical fragment that I do not understand.

According to my knowledge,「私たちには娘が四人います。」 roughly translates to, "We are four daughters."

However, I have also learned that the particle「に」is used to indicate direction, almost like the English, "to."

So I fail to see the reason why「に」is used in this instance, or what it is functioning as. It can't possibly translate to "to" like its more common usage, otherwise the sentence wouldn't make much sense. So perhaps there's another function for the particle that I do not know (or perhaps it isn't a particle in this case at all - although I know there is no character「に」in the word「たち」).

It would be appreciated if anybody could explain the reason for the particle's presence to me.

Thank you~

[Veridious]

Forgive me if I'm wrong, I'm a beginner as well, so I guess I'm testing my knowledge as well. But as far as I know に is used to give direction to verbs, in this case its giving direction to は I think, without に, the sentence would be saying something like We have four daughters I think, instead of we are.

Though grammatically both work, I think the に particle is used just to help specify the meaning in case there is no other context.

[Daniel]

Forgive me if I'm wrong, I'm a beginner as well, so I guess I'm testing my knowledge as well. But as far as I know に is used to give direction to verbs, in this case its giving direction to は I think, without に, the sentence would be saying something like We have four daughters I think, instead of we are.

Though grammatically both work, I think the に particle is used just to help specify the meaning in case there is no other context.

Ah, that does make sense, however, that gives rise to another question from me, why is the「に」unnecessary if I had to say「私はダニエルです。」to mean "I am Daniel?"
Would it then be correct to say「私にはダニエルです。」?

Thank you.

[becki_kanou]

I think it's OK to think of に as (something somewhat similar to) "to" in your example, if it will help to understand it.

私達には娘が４人います。
(belonging) to us are 4 daughters.

We often use this pattern to talk about relationships with people.
(X) には（Y）がいます. X has a Y.

Here are some of the first few examples from Google:
Aさんには、兄弟が3人います
A-san niwa, kyoudai ga san-nin imasu.
A has 3 siblings.

私には気になる男性がいます.
Watashi niwa ki ni naru dansei ga imasu.
I have a guy I'm interested in.

彼女には付き合って6年目の相手がいます。
Kanojo niwa tsukiatte rokunenme no aite ga imasu.
She has someone she's been dating for 6 years.

母にはたくさんの友達がいます。
Haha niwa takusan no tomodachi ga imasu.
My mother has lots of friends.

You don't need に in your second example because it's not a relationship, it's a simple equivalent. "I AM Daniel." not" I HAVE a Daniel."

[Daniel]

Oh, I see!!

That completely clears things up. I even had it initially translated incorrectly, too! Your explanation makes it completely understandable now, becki_kanou.

Thank you to both you, becki_kanou, and Veridious, for your instantaneous replies, and an extended thank you to you, becki_kanou, for helping me understand.

I appreciate it.

-Daniel.

[furrykef]

I think, without に, the sentence would be saying something like We have four daughters I think, instead of we are.

Don't you have that backwards?