Man kann der Einfachhalt halber "they" statt "he or she" schreiben. Die Problematik, auf die Sie gestoßen sind wurde unter dieser Adresse : http://www.oxforddictionaries.com/words/he-or-she-versus-they erklärt. Den für Sie wichtigen Teil habe ich hier schon einmal rauskopiert, damit es nicht nötig ist die ganzen anderen Absätze, welche den Ursprung des Problems erklären, zu lesen.
This can work well, as long as you don’t have to keep repeating ‘he or she’, ‘his or her’, etc. throughout a piece of writing.
You can make the relevant noun plural, rewording the sentence as necessary:
If your children are thinking about a gap year, they can get good advice from this website.
Researchers have to be completely objective in their findings.
This approach can be a good solution, but it won’t always be possible.
You can use the plural pronouns ‘they’, ‘them’, ‘their’ etc., despite the fact that, technically, they are referring back to a singular noun:
If your child is thinking about a gap year, they can get good advice from this website.
A researcher has to be completely objective in their findings.