My grandfather (German, age 12-16 during the war) described the Hitler Youth as being comparable to a modern "scouts" group. They were encouraged to learn to play musical instruments, go camping, have pro-Nazi party rallies, among other activities. But he mentioned nothing about being encouraged to have sex.

However, we do know of the Lebensborn which was a program set up by Himmler that essentially consisted of "breeding houses" where women were given the opportunity to meet and have children with SS officers and other eligible candidates with desirable "Aryan" traits. In some cases, female participation wasn't voluntary. The child was then given to an approved family in Germany to be raised.

Another interesting fact is that there existed the "Cross of Honour of the German Mother", given to a woman showing exceptional motherhood and has given birth to and raised at least four children. This award existed in three tiers. Interestingly, France has a similar medal that is still awarded to this date.

It isn't exactly what you were asking as I don't know of any examples, but I hope it provides some clarification.

Edit: According to this source, girls were told "You cannot all find husbands, but you can all become mothers", if that is any indication. But I see it as a preparation for the future when they become adults to be "good women", much like the way the boys were taught to be "good men".

Edit 2: Only slightly relevant: Russia also has an equivalent award and this and this are the Soviet predecessors.

There is anecdotal evidence of some 900 girls becoming pregnant after attending the 1936 Nuremberg rally.

Source - Michael H. Kater - “Hitler Youth”

Edited to add that I cannot find if this was part of a "breeding program" or a bunch of horny teenagers on the loose for a couple of days.