I'm sure that there are many children who learn Hungarian and German and Another language, easily. Hungarian isn't hard for a Hungarian baby who is growing up and living and loving the language each and everyday with papa and mama.
I think that if you add in a German time activities regularly and explain to baby that "Look, lets learn German colors. This is...., can you say....? Good job!"
Learn Vocabulary. Read books, do simple Q and A, do an activity. repeat. Enjoy.
Get one of those My first 500 Words in ___ books and use it as a guide to give your baby a good foundation vocabulary, and continually use it as a guide for learning more. Play games and read together and speak to her to help with sentence structure etc...
Have fun.