"en familie" is wrong?
Native speaker. No it is not. Apart from that you would for the most part say stiftet and not etableret.
Stiftet is still not given as an option when you hoover over established but at least it's marked 'right' now.
Same. Why is 'en familie' wrong?
I agree--why is it wrong?
As a native speaker I feel this transmation is wrong. It shoumd definitely be translated as "Hun havde stiftet familie". Note the idiom leaves out the indefinite article.
Is "etableret" as idiomatic as "stiftet"?
I feel like this could mean "She had established family." In the sense that she had a family that was established somewhere. Could it be written the same way?
This needs correction (or addition)...