Lease Addendum/Agreement for prospective tenant "holding"

Hi BP Fam!

I have a question regarding a prospective tenant with a move in date of June 25th, 2021. I currently have my Los Angeles unit listed on various websites and have a few people looking at the place. The prospective tenant understands compensating for the hold. I'm a little confused on how I should list the following breakdown in the lease agreement and addendum in order to hold it for her, especially because we are potentially losing out on more than half of a full month's rent and I believe we are being very fair with the below breakdown of cost. We also don't want to list anything as a "holding deposit" because the money will not be refunded.

Her move in date is June 25th, 2021. Security deposit is $1700. Rent is $1700. If we prorated her June rent, it would be $340 for her June 25th move in date. However, the landlord would only receive $2040 up front, if that's the case. The landlord wants to charge $3740 for security deposit, month of July 2021 up front and a $340 (which is her prorated rent amount for June). Instead of calling this a holding deposit, we want to charge July up front since it is the following week any way. Can someone assist me on how I should write this in a CA leasing agreement and addendum? Is this legal? Any feedback is much appreciated!

Thanks in advance!

Kasey