How often do ascendants change?

I feel like I heard it was every 10 mins. I probably can't figure it out but I'd like to know the possible ascendants my mum could have. She doesn't know what time she was born and doesn't know where her birth certificate is, and grandma said she was born early morning but doesn't remember the time.

Is it possible that I could narrow it down to a few? What can I do that can help me try and figure it out? By time, or personality/looks, anything, idk.

Posted by Jahlia
Every two hours.

Thank you 🙂