If you have a double name, know someone with a double name, or are the bestower of a double name, it's crucial to know the rules.
If you have a double name, you may find this collection of name-related knowledge useful, especially when it comes to politely.
The upshot is that you, Elizabeth Ann, should speak up unless you're fine with being called Beth.
Emma Carlton is a common example of a combination name in which both the mother and father agreed on the name and the mother's maiden name, Carlton, was added.
Although it is not uncommon for the mother's maiden name or another family surname to be used as the middle name, this is not a hard and fast rule.
Most parents learn the hard way with their first kid that this is a deeply personal decision that is frequently best made without the input and suggestions of friends and relatives.