Upvote:2
First things first: you obviously need to be permitted to enter Germany. If you hold UK citizenship, that is not an issue; if you hold Namibian citizenship you need a visa, for other citizenships you would need to check.
The Covid prevention rules are volatile and could change at any time, so it is imperative that you check they still apply when you are actually travelling. As things currently stand:
This can be checked on the RKI's list in German and in English.
In addition to the designated risk areas, entry rules are also volatile and may change on short notice. Currently, the situation is as follows:
This is summed up in the following picture by the Federal Government (in German):
Details and an FAQ can also be found in English on the web pages of the Federal Government.
Therefore, under the current rules you can enter Germany as triple-vaccinated adults during your ten hour layover.