Absolutely ask her father.
I got engaged September 2nd in Paris. Planned to do it, but not exactly where and when.
Asked her mum and dad a few nights before. Her dad was very appreciative that i asked. Her mum let me use her nan's 85 year old gold/platinum engagement ring to give her.
So, the saturday in Paris in a little Italian restaurant, the timing felt right. She was over the moon.
Went shopping the following week and got her a ring of her choosing and gav her mum her nan's ring back. (which has been willed to my fiancee anyway)
You should only expect to get married once....so get it right!
Good luck buddy.