My girlfriend had a miscarriage and I want to know what happened.
Why do you want to ask your girlfriend questions about her miscarriage?
I want to know more details about what happened.
I know you want to have more information about what happened, but you have to be sensitive to your girlfriend's mental state. This is a very traumatic event for her and when she's ready to share more information with you she'll share it. Be patient and give her the space she needs.
Patience. I will be patient. But I want to know everything about it.
I understand that and once time has passed you can tell her you want to know what happened. But do not question her like an interrogation, let her come to you.