"I can't consider them children anymore" has the same meaning, to me at least...yet it's wrong.
That's too bad. 'consider' or 'regard' are much closer the to point of 'betrachten', in my opinion.
@stbenjam: Has the same meaning to me too.
I can see them no longer as children....?????
@drtrocchi: This could be also correct. Did you report it?