Hi, I can help a little bit being a Czech :-).
Andulka is not "a little angel", it's really a form of a name Anna (it's the same name as Anne in English) and there are many forms of it. Annes are called Andulka, Andulièka, Anièka, Anka, Anèa and so and so. It was a popular name in the past (not as much today) and there are many Czech folk songs about Andulkas :-).
But the link to the song Andulko šafáøova is not very good, I'm sorry. It's a folk melody but the modern lyrics, and these are the bawdy ones. The link to lyrics posted here is OK :-).
I think this link is much better - this video is made for children to learn this song, you can read the lyrics as the song goes and see pictures to understand well :-). And here's a translation for you:

Andulka, the bailiff's daughter,
your geese are not at home.
Geese are in the barley field,
Andulka, go and drive them out,
drive them out of the barney field
before the day comes.

I would drive them out
if I was not afraid.
My mother is a light sleeper,
she knows every my moving.
I'm not allowed to leave my room
before the day comes.