"young Kateřina"

Translation: mladá Kateřina

[ClarkBHM]

Katka is short for Kateřina, yes?

[matanov]

Yes. Another short versions of this name are: Kačka, Káťa, Kačenka, Kačí ...

Fun Fact #1 - "kačka" and "kačenka" mean also "a (little) duck". (Note that the regular, most common word for "duck" is "kachna".)

Fun Fact #2 - "kačka" is also a slang word used for the Czech currency. It is derived from the abbreviation Kč (= koruna česká; i.e. Czech crown) which is spelled "ká čé". An example: Mám padesát kaček. = I have fifty crowns.