these are all fine, but you can also say "some pretty girls livestream online" .
you can use as a single word too, livestreaming, livestream etc...
But mostly we usually just say "stream","streamers","Streaming" etc.., the "live" part is often left out.
Also, the "online" part is completely redundant and unnecessary.
so these are better ways of how we would say
"some pretty girls steam to make money"
"streaming is a popular job these days"
"being a streamer can be stressful"
"she streams the whole process of removing her makeup"