Safety/anonymity and protection for clawing the money back are pretty much mutually exclusive.

 
You could probably do something with a smart contract but who is going to write the terms and how many providers or clients have crypto wallets to take advantage of the option? But given the number of crypto hijackings that have occurred I you might merely be trading one thief for another.

 
Probably best to just send a gift card you bought with cash and be willing to write it off -- a bit like if you TOFTT and it was not a good session.

You take a picture of it so she can access the numbers and send it via an encrypted email like proton. No method is 100% safe but I think this is the safest way to do it.

Thank you for the info.  Had thought about that, but didnt know if that option was generally ok.  

I’ve required a deposit to book for the last 12 years.

There’s many ways to supply a deposit. When I become a Mother I made the decision that I would never have my time wasted again. I don’t leave the house without a deposit. In everyday life people require deposits it’s no different. No one wants to have their time wasted. I’ve had individuals refuse the paper trail, so I send them to the bank to put $ in my children’s accounts. There’s always an option that works better for others & I am here to help. No deposit=no booking me.

My advise was to never give a deposit unless it is a very clearly reputable traveling provider.

For 14 years, I never asked for a deposit.  Unfortunately, I have to today.  I can't afford to lose money anymore due to the fact that either I would have a no call/ no show or a cancelation.  Hotel rooms cost too much these days.