Child benefit
Parents are entitled to child benefit until their child's 18th birthday if the child lives in Germany, in a Member State of the European Union or in a state to which the Agreement on the European Economic Area applies. If your child is training or studying, the entitlement is extended to a maximum of 25 years. The child benefit is granted on application to the Family Fund of the Employment Agency. Family funds in your area can be found on the Familienwegweiser.de http://www.familien-wegweiser.de/wegweiser/Familie-regional/Kindergeld/kindergeld.html
The child allowance can also be applied for online via the website of the Federal Employment Agency at www.arbeitsagentur.de/familie-und-kinder/kindergeld-online.
Child benefit offices Rheinland-Pfalz: http://www.kindergeld.org/familienkassen/rheinland-pfalz.html