Not sure what to suggest, but I'm the mama of a climber too. She started climbing around 4 months, a few weeks after she started combat crawling (very slowly and un-coordinated- took 10 min to get about 30 cm ahead). She wasn't even sitting unasisted at the time (not until a few weeks ago, in fact), and she also didn't start crawling until recently. We spent a lot of time on the sofa, she'd climb on the back of it, I'd keep her safe. We've got the washing rack behind the sofa, so she loved climbing on that. I was a bit stuck there, but DD doesn't like that I leave her anyway.