Paying Podcast Guest In Full Before Appearance?

I have a YouTube channel of about 3.3k subscribers and have been in talks to get a fairly big guest on my show. The woman has some celebrity and is a pretty big name on the internet who gets big numbers on clips talking about other celebrities. Her producer gave me the figure that she charges. Should I suggest that I make a partial payment before she appears on my channel? I'm just worried in case I make the full payment, she ghosts me or I get fobbed off with excuses and she ultimately doesn't make the appearance.