Is Zeilinger a Jewish last name?

Question:

Is Zeilinger a Jewish last name?

Sorry, I may have misspelled the name. The mother of a friend of mine was born in Vienna in 1939. Then was adopted under strange circumstances. She won't talk about her birth family in detail. She only mentions her brothers in passing. Could anyone help please? If she is Jewish the daughter would like to know because the mom is very ill. And she doesn't want to bury her inapproprietly. Any help would be appriciated. Thanks.

Additional Details

1 month ago
Sorry, I should have gone into a bit more detail. Her mom grew up in Austria during World War II. Her mom never talks about her childhood. Asking her anything about that time just completely upsets her and freaks her out. She doesn't want to hurt her mom or bring back bad memories for her. That's why we're trying to do it this way. Thanks.

1 month ago
Thank you to everyone for answering. You've been a big help.

Best Answer - Chosen by Asker: 1 month ago
Sorry, I should have gone into a bit more detail. Her mom grew up in Austria during World War II. Her mom never talks about her childhood. Asking her anything about that time just completely upsets her and freaks her out. She doesn't want to hurt her mom or bring back bad memories for her. That's why we're trying to do it this way. Thanks.