We came to Munich 2 months back. We approached Realschule and Gymnasium, and both refused to take our 8-year old as she did not speak German. Only option left was Hauptschule, which I read from reviews is ranked lowest in the schools. What are the options that a non-German parent has in such situation? I also have a 13 year old, for whom the problem is even further worrying.
If she is 8 years old, that would put her at "Grundschule" (elementary school) levels in Bavaria. More specifically, in 2nd or 3rd grade, depending on month of birth and previous educational levels.
Also a lot of elementary schools will have special courses for German as foreigners.
During 4th grade, depending on her overall grades she can then choose a secondary school, which can be "Hauptschule" for grades 5 through 9 (or 10), "Realschule" for grades 5 through 10 or "Gymnasium" for grades 5 through 12/13.
What are the options that a non-German parent has in such situation?
Ask school and authorities what they can offer to make your child learn german.
There is no help in putting a child into a normal school if it doesn't speak at least basic words of a language.
Your daughter would be bored all day and have no idea what happens around her. She wouldn't learn anything if she doesn't understand what others say. Grades would be bad and demotivating. Finding friends is hard too. In summary, she would have a very disappointing time.
Later when she leaves school (probably not finish - just leave) you might see all this was useless.
If school refuses to place your child somewhere without any sense then it's your chance to avoid asking "why didn't we ..." in a couple of years when it is too late.
Instead you have the chance to set the direction of her future now.
Please use this chance!