But there is a practical exception for minor "T&E" costs. If you've ever travelled for business you know that acronym stands for "Travel & Entertainment" expenses.
For T&E expenses in the M&G context, that means it's a good idea to offer to cover small costs of getting to the meet, like parking fees, valet costs (plus tip), gas if it's a long drive or an Uber. Of course if you meet for a drink pay for the drinks. Give her the $20, $30, $40 (max!) when you two finish the M&G. Or order her UBER on your app (beware this is not always a good idea.)
But other than that let her know you won't give her any cash before meeting face to face. So no allowance to get her hair and nails done for you, to fix her flat tire so she can drive, to pay her for her time while you watch her suck down a caramel crunch frappe, etc. That is all either scammer language or a seriously entitled GPS bitch who must be avoided. Bottom line: if she WANTS to meet you, she will find a way to show up. If she wants to get endless cash and never meet you, she will find every reason why you need to pay in advance.
Now it's not uncommon (and for some standard procedure) to go directly to BCD after the M&G. I've done it a few times, but I generally make it clear that the M&G is a brief meeting (20-30 minutes) to work out arrangement details, and that we can agree on our 1st date night if we align on those details. If you want to/expect to do a same-day close, then have sufficient cash on hand. Note sufficient does not mean carry $5k in your wallet to look like the BSD (Big Swinging Dick) of your local Starbucks! It's entirely possible that her pimp/BF/co-scammers are waiting nearby with weapons. Exercise due-diligence about safety and security.
As to how to hand over the cash: For small gifts (the T&E cash), I bought a box of 50 small greeting/note cards with colored envelopes. Put the cash in there and write something nice on the card like "Thanks for meeting! Looking forward to next time!" You can just hand her the envelopes anytime in public - like a birthday card.
For full allowance amounts, I also use a standard (small) white envelope, until a few dates down the road when I ask her if I can pay by Zelle or Cashapp (do not use Paypal - but that's another post). I really don't like the optics of handing her a wad of $20's "hooker style" (and yes, I get the irony). The envelope isn't perfect, but I think it's better.
Life is good
The Cat