Why is she crated? Is she crated in your bedroom? If not, she might be lonely. If so, perhaps try 15 minute intervals. If it were my girl Brooke, if she gets up, she has to go. If it's Ben or Brooke, I can tell them to lay down for awhile. That's why I suggested shorter intervals in case it's legit.
If she goes out and goes right away, then you'll know she needs to go as opposed to sniffing around for a bit outside and can wait a bit. Brooke runs to the door so I know she needs out and sometimes it's 4 or 5 am. I've learned when in doubt, let her out.