妹いもうとと 2人ふたりで京都きょうとに来きました。
My younger sister and I, the two of us, came to Kyoto.

N（Person）と　N（Number）で: Used when saying who with and how many of you did the action.

Structure

兄あにと 2人ふたりで旅行りょこうに行いきました。
My older brother and I, the two of us, went on a trip.
まえは、母ははと 2人ふたりで来きましたが、こんかいは 1人ひとりで観光かんこうします。
My mother and I, the two of us, came together before. But today, I will be touring alone.
家族かぞく 4人よにんで食事しょくじします。
Our family of four will eat.
今日きょうは友ともだち 2人ふたりと京都きょうとに来きました。3人にんで京都きょうとを楽たのしみます。
My two friends and I came today. The three of us will be enjoying Kyoto.

“で” is used to indicate the total number of persons who will do or did an action together.
The speaker is included in the number of persons.
When indicating the number of persons with “と” the speaker is not included in this number.