Here are some ways to express it, depending on the desired nuance:
* Chikash (chik-ash): This refers to a "child" or "baby" in general, regardless of gender.
* Chikash-hish (chik-ash-hish): This literally means "child-female," but could be used to denote a baby girl.
* Icho-hish (ee-cho-hish): This means "little girl" and could be used for a baby girl.
* Chikash-hish anumpish (chik-ash-hish a-num-pish): This translates to "baby girl" literally, using "baby" and "female" terms.
The best way to say "baby girl" in Choctaw might depend on the context and your desired level of formality. Remember that Choctaw is a living language, and usage can vary between individuals and communities.