Quick answer
Yukiko is a girl name.
Meaning and history
From Japanese 幸 ( yuki ) meaning "happiness" or 雪 ( yuki ) meaning "snow" combined with 子 ( ko ) meaning "child". Alternatively, it can come from 由 ( yu ) meaning "reason, cause" with 喜 ( ki ) meaning "joy" or 貴 ( ki ) meaning "valuable" combined with 子 ( ko ) meaning "child". Other kanji combinations can also form this name.
Notes and context
Usage: japanese | Japanese Hiragana: ゆきこ; Japanese Katakana: ユキコ